X-23 vs Sillhouette
Ok, I know everyone hates X-23 but this is supposed to be about who would win in a fight, not the "Contest of Popular Marvels" so let's get that out of the way from the start
X-23, while a clone of wolverine does differ in several key areas. Firstly she doesn't have an adamantium skeleton. She posseses addamantium claws but was able to escape from weapon x before they applied the metal to her skeleton. Now you may initially think this puts her in a weaker position...HOWEVER, as her healing factor doesn't have to combat the adamantium that wolverine's does so it is actually considered to be more effective than his. To remind anybody not fully versed in wolverine's mythology, in a similar way to cable's telepathic abilities being used to keep the techno virus at bay wolverine's healing factor has always been restricted by having to stave off adamantium poisoning. Taking this into account I can't work out any way for Silhouette to do any damage to X-23 that she couldn't simply shrug off.
Ok, there are certain powers the silhouette has that are ideally suited to this location. She can shadowmelt rendering her almost completely invisible. The downside to this is that x-23 has all of senses heightened. If she can't see silhouette she can certainly smell her or hear her heartbeat.
Silhouette can also teleport to a limit extent (although she finds it something of a strain (remeber she is a mutate not a mutant. Her powers are not on the same level as say nightcrawler or cloak (even though cloak's technically a mutate too(way to many brackets in this sentence...))) This is all well and good but we are talking about x-23 here! Silhouette can only teleport between existing shadows and x-23 has reflexes that are beyond superhuman.
Once the fight reaches close-combat not only does she have the adamantium claws (it sounds harsh but she cold simply slice silhouette's crutches in half, as she's paralyzed from the waist down this would render unable to defend herself, possibly even to continue the fight full stop) but she is a vastly superior martial artist and infinately more agile than silhouette. She has fought wolverine (who is considered to be the greatest close quarters fighter in the marvel U) to a standstill, endured the rigourous training endured during weapon x (government training is good but there's really no conditioning like the constant threat of cattle prods and a slow-painfull death...) and has the aforementioned heightened strength, reflexes, stamina, agility...need I go on? Silhouette is completely outclassed in this department. To close this point I shall quote the mighty wikipedia
wikipedia said:
X-23 received intensive training in ranged weapons, explosives and charges, and both armed and unarmed martial arts. Her skills are so advanced that during the New X-Men's confrontation with the advanced sentinel code-named Nimrod, she was the only member of the team that the sentinel assessed as a severe threat.
yes this arc of new x-men occured after the contest of marvels started, but it is not a new ability, it is simply a characters assesment of all of her existing abilites. Therefore I believe it is admissable (I always wanted to be a lawyer when I was a kid

)
The only trick I can think of is that silhouette's crutches contain a poison designed to paralyse it's recipients. Firstly she has to get in a position to hit x-23 with this suomewhat cumbersome weapon, near impossible. Secondly, her healing factor is GREATER THAN WOLVERINE'S! To use a car metaphor. Wolverine and X-23 are like the BMW M3, they both have masses of power under the hood, but crucially, x-23 has had the adamantium restrictor plate removed whereas wolverine is still stuck topping out at 150mph. Wolverine has survived a nuclear missile landing on him. There is no way silhouette could ever incapacitate X-23. Her system would scrub any poison or tranquiliser she got hit with and any blows silhouette managed to land would be nothing more than a few seconds inconvenience.
X-23 WINS!