fighters in general-ps2
online fighters-360/pc
my personal choice for fighters is dc though, lots of great stuff
PS2, unbeatable… and PC, for the Doujin stuff like Akatsuki, B3, Monster, EFZ and others… also: Emulators, and dont throw me that “illegal issues” shit, there are a lot of fighting games that are now almost impossible to play without an emu.
As of now the PS2, in future though probably the 360.
The Wii is the future…of 2d fighters, thats only if a plane crashes in the ps2 factory and blows up every ps2 system in stock this will trigger everyone ps2 to blow up simultaneously around the world.
PSP. Test it there, maybe release on consoles later…
PS3, has a built in ps2, GG, then later gets the other releases. 360 is great, but I’ll follow history with ps2 getting most of the fighters, same most likely will happen with the ps3.
I think 2D fighters will become XBLA and PSN titles while the bigger 3D games like Tekken and Virtua Fighter will be 360/PS3 titles. So it might be better to get both systems this gen.
i personally have a slim ps2 with swap magic and most of the popular fighting games, but im seriusly thinking of getting a next gen system this christmas, but i cant decide if a 360 or ps3:looney:
i would get a 360 cause it has the better port of virtua fighter 5!!!
and i would get a ps3 cause oh heck i just cant decide:looney:
Recent news article:
http://www.bloomberg.com/apps/news?pid=conewsstory&refer=conews&tkr=MSFT:US&sid=a0FYuTjLAMec
My opinion for next gen:
Japanese games -> ps3
US/European games -> xbox 360
and of course Wii is outselling both of them everywhere by a long shot lol 
i think it depends now. if you want a lot of 2D games than ps2 is the way to go if you can play imports, but SNK is being pretty good at bringing some games over now. mvc2 just for the dreamcast. newer 3D fighters like tekken 5 dr, tekken 6, soul calibur 4, virtua fighter 5 than i’d stick to ps3. DOA4, online VF5, soul calibur 4, plus 2d fighting games coming on live arcade for X360.
The PS2 has what you need for now. But the Wii is bringing SNK to the VC, and Xbox Live bringing all the remakes and the online element to the games, and the PS3 has Tekken, at least for now in theory. That is probably how it will filter itself out. It seems like you may need more than one if not all 3 to get all that Fighting Game goodness.