AAA to me means a game that manages all of the following:
a) game has that mysterious 'it' factor you know when you play it but is hard to pin down - or to paraphrase the judge commenting on recognising pornography the 'I know it when I see it' factor
b) game is marketed as a leading title (whether single platform or multi) with strong promotional activity
c) game sells well (at least 2 M)
d) game is pretty much unanimously praised by critics
e) game is pretty much unanimously praised by gamers
f) game is perceived to encourage sales of a particular console (although I think this one is sort of optional as late in a consoles life this might not happen. For example God of War 2 is a AAA title but I doubt it shifted that many extra PS2s globally)
So surprise hits don't count (although they could give rise to new IP and become AAA franchise).
AC is arguably a AAA title but I feel it just fell short with critics and general gaming public due to lack of overall gameplay finesse and repetition of core elements. I suspect AC2 will be a bona fide AAA title though.
Individual favourites don't count - sure I could be the only person in the world to love an individual game (and to me I guess its a AAA title) but to the gaming public at large its not a AAA title plain and simple.
Therefore, for me, very few games are really AAA titles.
