FettsBabe:
The PS2 lineup is pretty dang good, IMHO:
TTT - I seriously want this game, looks beautiful, moves like Tekken should - deep fighting gameplay. Excellent.
SSX - Amazing graphics and deep gameplay - I don't like snowboarding games, but this is really good.
Madden 2001 - the only football game to consider for the PS2
AC2 - my favorite so far. Hard as heck, deep, excellent graphics, mech customization to all get out. Awesome.
Summoner - Good looking RPG, but hard to tell from a rental. Excellent story, some grphical glitches.
Timesplitters/Unreal Tournament - both great multiplayer FPSs but both lack a bit without friends to play against.
Sky Oddessy - Difficult but fantastic flight sim!
But I also still enjoy PS1 games on my PS2 such as the new Final Fantasy IX. Bdawg is right about FFIX being awesome!