MW4 is a great game, well worth playing. As for other games to check out, there were a ton of platformers trying to ride on Sonic's mascot coat-tails; even when they don't work well, they're usually at least interesting.
@bj @NovaSquirrel Ristar was pretty cool too. That came before Sonic, I think.
-F
@Felthry @NovaSquirrel Yes and no. Ristar was based on a character they were sketching ideas for before they came up with Sonic, but his game came out after Sonic 3. It's a great game, too.
Ones I'd recommend are Pulseman (made by Game Freak in their pre-Pokémon days, and the art style definitely bears that out), Rocket Knight Adventures, and Socket (which is not a great game but I think it's sort of charming and it has good music).
@NovaSquirrel @bj Our main knowledge of genesis games basically starts and ends with the Phantasy Star series, which I don't think is really your thing, so I'm afraid we can't really help any further
-F