Oh, wow...this is tough. I'm going mostly on what I own or have seen in person.
1. Dr. Doom PF: in terms of quality, detail, and presence, this thing can't be beat.
2. Spider-Man Com: a massive Spidey, great sculpt and paint, great pose, this piece really captures Spidey in all his glory.
3. Hulk Maquette: Huge piece. Some people think this is low quality because of its weight...they are wrong. This piece rocks...looks like it came right out of the movie.
4. Venom Com: I was blown away by this one when I first saw it in person. Has a feeling of immense size, even though he's crouching down. I love the claws and the detail on the suit/skin. Very nice piece.
5. Iron Man 2 Mark VI Maquette: detail is exceptional, and I like th elight up feature.
6. Hobgoblin Com: even though this is 1/5 scale, I love the character, the pose, and the detail. The cape looks great.
7. Wolverine PF: the metal claws make this piece. It's kind of small (I know that's because Wolverine is small in the comics), but has really nice detail, and his arms look great.
8. Thor PF (comic version): HUGE piece. Mine was damaged during shipment, and I had it fixed and cusomized into a modern costume Thor. I am really happy with the results, but I love the original costume too.
9. Deadpool PF: I am going to throw this guy on th elist based on the early in-hand pics. Mine is coming next week and I can't wait.
10. This spot up for grabs, but I'll give it to Back in Black Spider-Man right now. The black costume is my personal favorite. That said, upcoming pieces like Galactus and Gladiator Hulk will probably earn a spot on my list.