I definately regret buying MW2 on release, i was expecting it to have the excellent quality story of the first one and up the action. Up the action YES, but completely lacklustre story compared with the first, completely over the top. Not only that but it just finished, it has to be one of the poorest endings and possible cliffhangers ever.
As for the online it was just more of the same, at least BlackOps did something new, and better. The only decent part of the game was Spec Ops. It's a shame because the opening few levels where quiet good, unfortunately it just got worse.