I've been a huge X-Men fan since I was a kid (although my interest really began to wane when Claremont left to start X-Treme X-Men following his removal from the main two books, post-Revolution), so I'm firmly on that side of the room. As for favorite team era, it would probably be the early 1980's Claremont/Byrne team consisting of:
-Banshee (pre- losing his voice)
Throw in the "Dark Phoenix"-era ancillary supporting team members (Beast, who was, ironically, a member of the Avengers at the time, Angel, Dazzler, and Kitty Pryde) and it was pretty much the perfect era, both creative team and character team-wise, for that book, in my opinion.
That being said, the current lineup in "X-Men Forever" is pretty nice, too:
...with Cyclops, Professor X, Nick Fury, Sabretooth, and "Storm" as supporting ancillary characters
(Favorite other X-Team of all time was the second incarnation of X-Factor, with Havok, Polaris, Jamie Madrox, Wolfbane, and Strong Guy, written by Peter David)