Originally Posted by pr0xyt0xin
To the best of my knowledge...
Fox currently owns the movie rights to:
Fantastic Four (Silver Surfer, Galactus)
X-Men (all X-Men characters except I believe Quicksilver/Scarlet Witch are shared with Marvel/Disney)
Daredevil (Elektra, Bullseye,) [Kingpin was on loan from Sony]
and Sony owns the movie rights to:
Spider-Man (and Spider-Man's villains including Kingpin)
Marvel/Disney owns the rest I believe. The studios have to make a film every 7 years or so otherwise the rights revert back to Marvel. And I specify "movie" rights because as you may have seen the Ultimate Spider-Man cartoon is currently being made by Disney.
EDIT: Just found out Daredevil is back in Marvel/Disney's pocket.
I'd also note that Fox owns Super-Skrull by way of FF, but Marvel has the rights to the Skrulls as an alien race. And although Namor is technically a mutant, Marvel has the rights to him; he is not specifically an X-Men character.