Nine times out of 10 the differences are so minuscule that you will never notice them unless they are running side by side. So I always buy the game for my favorite platform, Sony. To me, controller preference / eco system preferences / etc. trump any minor differences.
^^^ This. There are some cases, Sonic Heros comes to mind. The Gamecube version is slightly better than the PS2 version and while I don't own it like I do the others I've heard the Xbox port was awful with frame rate and such.
That's not exactly true. The game runs on a modified Sonic Adventure 2 engine, and the Gamecube version is considered the best because its very stable( 60 fps) and has the best shadows, while the Xbox has better resolution and sound options and is very good. The PS2 port is pretty bad, with sub 30fps most of the time, graphical glitches, loading times, etc., and one can tell that the game was not originally suited with the PS2 in mind and the port seems rushed. The only reason Sega released this game on the PS2 was that apparently Sony threatened to bar them from publishing anymore games on their system if there was no PS2 Sonic Heroes port.
Really, good to know. Everyone I've talked to said the Xbox was the worst port, yeah the PS2 has some issues. Makes a lot of since the GCN is the best version considering SA2B was made for the GCN especially and Heros is running on a modified version of its engine.
Yeah, I believe Sega managed to use the same engine for the Xbox version, although the PS2 version uses Renderware, and that port job was done by Sega of America. That PS2 version is pretty rushed, and they really should have taken more time on the port since it has alot of problem that hamper the gameplay experience. Most of the other Sonic PS2 games like Shadow the Hedgehog, Sonic Riders, and Sonic Unleashed run pretty badly for the most part, so its usually better to pick it up on other platforms, since Sega( and other companies) couldn't find ways to bring out the best of the PS2 performance thanks to its complex architecture.