Best of the series, and worth a try.
It's a well-attested fact that movie adaptations are bad games. Though #2 was a good try, USM really kicks things into high gear. The cel-animation style is perfect, the animations are great, and the artistic style of the city is consistent and likeable.
Venom is a LOT of fun to play, and you really feel like a true monster; bounding around Manhattan eating people and throwing cars around.
The main story is a lot of fun, though a bit short. I am a strong believer that super-hero games need to be open-ended (the whole "powers = responsibility" thing fits this idea) because heroes should be free. I applaud the makers of Ultimate Spidey credit for doing this, and for doing it well. One wonders if Batman will EVER make it into an open-ended game...?
Whether you have a PS2, PS3, X-Box, or 360, this game is worth picking up. You can find it used for under ten bucks, and it is the best of Treyarch's series of Spidey games.