So let's analyze the likely/possible villains, based on the comics...
#1-3 were about the Brood, which we haven't seen yet, though the whole alien parasite thing would be a bit too scifi IMO.
#5-6 were about the Silver Samurai and Viper. The Wolverine took them, so no go there.
#7 was about the Hellfire Club. They were used in First Class, so likely not going to happen.
#8-10 is about Nova Roma. This one's a possibility as it uses Selene and has the New Mutants fighting in an arena...
#14 is about Magik (and the New Mutants) battling S'ym. Although it's kind of the start of her next level of powers, it's really a short story, but elements could be used.
#15- 17 is about the New Mutants battling the White Queen and the Massachusetts Academy. This would have been perfect, but Singer and Kinberg have ruined the White Queen by killing her. Personally, I want to see the White Queen again running the Hellions, so they should do a Professor X, where Emma put her mind (prior to being killed) on the Astral Plane so she could take over the body of someone else. Not ideal, but it would bring back the White Queen so we could get the Hellions.
#18-20 is about the Demon Bear, but that is too specific to just Dani.
#21 is the introduction of Warlock.
#23-25 is about Cloak and Dagger. I don't believe that Cloak and Dagger would be usable by Fox, though they would make for a great TV series...
#26-28 is about Legion. If they are going to use him in a different show/story then it won't work here.
# 29-34 is a whole story thing about Amuhl Faruk taking over Karma and more gladiator stuff. Just not so sure the whole astral plane thing will work well here.
At this point they would have also had some dealings with the Beyonder (who is not usable) and Asgard, where Dani has become a Valkrie, but again, not usable due to Thor and Avengers.
There's more Watcher, Hellions and Legion stuff.
Magneto becomes Headmaster (which could be interesting)...
#46-47 is about the Magus (no, not that Magus). It's effectively a techno-organic bully who is Warlock's (no, not that Warlock) father. (I just realized that the New Mutants Warlock and Magus are identical name wise to the Adam Warlock/Magus...
The New Mutants then go to space for a while and meet up with the Starjammers (which I believe would be better introduced in X-Men) and Lilandra (again, better for that to be the X-Men).
We get Birdbrain as a character (don't get me started)...
Bird-Brain leads to the Ani-Mator, which is a really lame Sinister, who creates half animal/half human creatures. This does lead to Cameron Hodge though...
Cypher dies during the Ani-Mater story, but
There's this whole story that starts back up in space, includes more of Lila Cheney, and ends with S'ym (infected with the transmode virus) escaping Limbo to try to take over the world.
In #74-75 the New Mutants "fired" Magneto as their Headmaster, while there was more Hellfire Club stuff.
#76-86 was more Asgard (and Hel) and Brotherhood stuff.
#86 introduced the Mutant Liberation Front, and soon after we meet Cable and Stryfe.
#95 gets us into the whole X-Tinction Agenda storyline. Warlock does die in this episode. This gives us more of Cameron Hodge, and introduces Genosha. This one is a crossover with the X-Men team.
#98 introduces Gideon, Deadpool and Domino (though really, it was Copycat).
#99 introduces Shatterstar and Feral, and Warpath joins with the motivation of revenege against the Hellfire Club and Emma Frost.
#100 was the final issue and the start of the transformed team as X-Force.
So, what does this summary give us? Well, from this it seems we are limited in viable villains. Let's break them down...
1. The Brood: It's the whole alien symbiote thing. Not so sure this would be the best option.
2. The Hellfire Club: It would have to be a different line-up due to the whole First CLass thing. No Shaw and (thanks a lot Kinberg and Singer) no Emma Frost. Already used, so I think there's better options.
3. Selene and Nova Roma: Although I definitely think Selene is a strong candidate for a villain, I'm not so sure the whole Roman theme of Nova Roma would work.
4. The White Queen and the Hellions: This would have been perfect if Singer and Kinberg hadn't ruined the White Queen, but, I have a way to fix this...
5. The Demon Bear: Too specific to Dani. Don't think this is the best option.
6. S'ym and the whole Limbo thing: Although I want to see this is the New Mutants, it's very specific to Magik, so I'd prefer this as a second movie story.
7. Magus (with Warlock): This would be a great story for a New Mutants movie, though the CG would be crazy.
8. The Mutant Liberation Front: Perfect villain group, though I would save this for X-Force, especially as it applies directly to Cable (with Stryfe).
9. Cameron Hodge and Genosha: Again, great storyline, even if it's a crossover, but this would likely be better down the road.
So, here is what I would like to see...
In their first movie, since it will require the formation of the team, have the Hellions as the main adversaries. But who would lead them? Well, that would be Selene! Yes, that's a major change from the comics, but Selene could take the White Queen's place due to where we are in the X-Men movieverse...
After the Hellions/Selene it seems like the whole Limbo story would work and then we could head towards Genosha (and maybe a crossover?).
That would be three viable New Mutants movies that would get us to the formation of X-Force where we'd get the Mutant Liberation Force and Stryfe!
#1-3 were about the Brood, which we haven't seen yet, though the whole alien parasite thing would be a bit too scifi IMO.
#5-6 were about the Silver Samurai and Viper. The Wolverine took them, so no go there.
#7 was about the Hellfire Club. They were used in First Class, so likely not going to happen.
#8-10 is about Nova Roma. This one's a possibility as it uses Selene and has the New Mutants fighting in an arena...
#14 is about Magik (and the New Mutants) battling S'ym. Although it's kind of the start of her next level of powers, it's really a short story, but elements could be used.
#15- 17 is about the New Mutants battling the White Queen and the Massachusetts Academy. This would have been perfect, but Singer and Kinberg have ruined the White Queen by killing her. Personally, I want to see the White Queen again running the Hellions, so they should do a Professor X, where Emma put her mind (prior to being killed) on the Astral Plane so she could take over the body of someone else. Not ideal, but it would bring back the White Queen so we could get the Hellions.
#18-20 is about the Demon Bear, but that is too specific to just Dani.
#21 is the introduction of Warlock.
#23-25 is about Cloak and Dagger. I don't believe that Cloak and Dagger would be usable by Fox, though they would make for a great TV series...
#26-28 is about Legion. If they are going to use him in a different show/story then it won't work here.
# 29-34 is a whole story thing about Amuhl Faruk taking over Karma and more gladiator stuff. Just not so sure the whole astral plane thing will work well here.
At this point they would have also had some dealings with the Beyonder (who is not usable) and Asgard, where Dani has become a Valkrie, but again, not usable due to Thor and Avengers.
There's more Watcher, Hellions and Legion stuff.
Magneto becomes Headmaster (which could be interesting)...
#46-47 is about the Magus (no, not that Magus). It's effectively a techno-organic bully who is Warlock's (no, not that Warlock) father. (I just realized that the New Mutants Warlock and Magus are identical name wise to the Adam Warlock/Magus...
The New Mutants then go to space for a while and meet up with the Starjammers (which I believe would be better introduced in X-Men) and Lilandra (again, better for that to be the X-Men).
We get Birdbrain as a character (don't get me started)...
Bird-Brain leads to the Ani-Mator, which is a really lame Sinister, who creates half animal/half human creatures. This does lead to Cameron Hodge though...
Cypher dies during the Ani-Mater story, but
There's this whole story that starts back up in space, includes more of Lila Cheney, and ends with S'ym (infected with the transmode virus) escaping Limbo to try to take over the world.
In #74-75 the New Mutants "fired" Magneto as their Headmaster, while there was more Hellfire Club stuff.
#76-86 was more Asgard (and Hel) and Brotherhood stuff.
#86 introduced the Mutant Liberation Front, and soon after we meet Cable and Stryfe.
#95 gets us into the whole X-Tinction Agenda storyline. Warlock does die in this episode. This gives us more of Cameron Hodge, and introduces Genosha. This one is a crossover with the X-Men team.
#98 introduces Gideon, Deadpool and Domino (though really, it was Copycat).
#99 introduces Shatterstar and Feral, and Warpath joins with the motivation of revenege against the Hellfire Club and Emma Frost.
#100 was the final issue and the start of the transformed team as X-Force.
So, what does this summary give us? Well, from this it seems we are limited in viable villains. Let's break them down...
1. The Brood: It's the whole alien symbiote thing. Not so sure this would be the best option.
2. The Hellfire Club: It would have to be a different line-up due to the whole First CLass thing. No Shaw and (thanks a lot Kinberg and Singer) no Emma Frost. Already used, so I think there's better options.
3. Selene and Nova Roma: Although I definitely think Selene is a strong candidate for a villain, I'm not so sure the whole Roman theme of Nova Roma would work.
4. The White Queen and the Hellions: This would have been perfect if Singer and Kinberg hadn't ruined the White Queen, but, I have a way to fix this...
5. The Demon Bear: Too specific to Dani. Don't think this is the best option.
6. S'ym and the whole Limbo thing: Although I want to see this is the New Mutants, it's very specific to Magik, so I'd prefer this as a second movie story.
7. Magus (with Warlock): This would be a great story for a New Mutants movie, though the CG would be crazy.
8. The Mutant Liberation Front: Perfect villain group, though I would save this for X-Force, especially as it applies directly to Cable (with Stryfe).
9. Cameron Hodge and Genosha: Again, great storyline, even if it's a crossover, but this would likely be better down the road.
So, here is what I would like to see...
In their first movie, since it will require the formation of the team, have the Hellions as the main adversaries. But who would lead them? Well, that would be Selene! Yes, that's a major change from the comics, but Selene could take the White Queen's place due to where we are in the X-Men movieverse...
After the Hellions/Selene it seems like the whole Limbo story would work and then we could head towards Genosha (and maybe a crossover?).
That would be three viable New Mutants movies that would get us to the formation of X-Force where we'd get the Mutant Liberation Force and Stryfe!