I've always favored the secondary X teams (Exiles, X-factor, Excalibur) over the X-men proper. Maybe because the "B" X-teams are less prone to editorial interference and random cross-overs.
I agree completely. The "second tier" X-Books have been better because they can tell the stories that aren't the focus of the entire Marvel U.
My favorite second-strong character is Layla Miller. Mutant starring in PAD's current run on X-Factor. It is worth noting, however, that she was born inside the pages of House of M, a gigantic Marvel crossover event