Favorite SEGA game ever

Hey everyone i just wanted to know whats everyone's favortie game ever on a sega system

I would have to say NiGHTS or maybe Shining Force 3
I'm pretty sure Dark Savior is made by Climax, not Sega. As for picking a favorite Sega game, I can't; they've done a whole lot of really nice stuff.
Big shock - Akuma likes SF2A ;)

If we go by most played (hard to pick a fave) I'd have to say fIGHTERS MEGAMiX or House Of The Dead for Sat. Or maybe Phantasy Star II for Genny. Or House Of The Dead 2 for DC. Hard to pick just one. Best game? Probably PDS for Sat. Very well done little epic they put together there.

Of course, I'm trying to think of just Sega titles - if we get into third party games too it's over. Too many sick games.
I'd go for Streets of Rage II, but Spikeout is on the top for me too! Anyone know if it's gonna be out for the dreamcast?
I'd say Mr Bones ! Though not perfect, it's the funniest game I've ever played. Maybe I'll add Golden Axe II on system32. Can't wait for the next version of modeler... There may be a release in 2 or 3 years :/