Spider-man -- Are we gonna have dual continuities at once? If so, I suggest an Ultimate Spider-Man styled show...
Spider-girl -- Please no... I like her, but the concept of M2 irks me.
X-men -- Most promising... young X-Men, either Scott and Jean's early days or ICeman and Rogue post X3... or a totally fresh conceptualization, but keeping young mutants means you can excuse minimal power use and the teen drama that people seem to like so much.
Silver Surfer -- TV budgets are not ready for what Silver Surfer should be...
DD -- The most cost effective, but bad word of mouth from the movie still exists... furthermore, I personally am not too interested in it, though it would be a great show, I doubt I'd watch it too often unless it was REALLY good...
FF -- TV Budgets are also not ready for what the FF should be doing...
Avengers -- West Coast Avengers... sure, but TV Budgets (or contracts) are not ready for Captain America, Iron Man and Thor... especially not all at once.
Capt. America -- Could be cool, especially if SHIELD played a heavy role in everything. Nick Fury is one kick-butt supporting cast member.
Ironman -- Maybe... but Iron man should be doing more than TV budgets can handle...
Just the major heroes -- Nah. You need Cloak and Dagger, that would make one of the best TV shows evah. Smaller, lower powered characters can stay in budget, because TV just can't afford an all out slugfest between Iron Man and Fing Fang Foom over japan. They just can't.