4 player console games?

[CGRemakes]

I am in the process of getting ready to drill my CP.  I will be using my cab primarily for console games (it will be able to play DC, GC, PS1, PS2, XBox games).  I have several 4 player games, so I will be building a 4 player CP.  I know for those who build 4 player MAME cabs, they usually only use 4 buttons for the 2 outside players.  However, are there many 4 player console games that use more than 4 buttons?  For example, does Tekken Tag, DOA2, etc?  I won't be playing Madden or any complicated sports games on the cab, mostly just like NBA Showtime/NFL Blitz (I know they only take 3), but I will be playing Tennis 2k2 and some 4 player fighters.

[TalkingOctopus]

Tekken Tag uses 5.  2 for punch, 2 for kick and 1 to switch player.  I don't really like Tekken tag all that much.  I think 4 is much better.  Not ansolutely sure about DOA, but I think it uses 4.

[abrannan]

Guilty Gear Isuka may have more buttons, but I don't know.  GGXX had at least 5, and Isuka will be adding a facing button, but I don't know if they're taking out one of the other buttons.