I've been an X-fan since 1991 (second only to being a Transfan) but I wait for the trades these days. I'm currently buying:
Astonishing X-Men
X-Men: Legacy
Uncanny X-Men
X-Factor
New Exiles
A couple of other Marvel heroes:
Captain America
Daredevil
Runaways
She-Hulk
Thunderbolts
Young Avengers
All the Ultimate books:
Ultimate X-Men
Ultimate Spider-Man
The Ultimates
Ultimate Fantastic Four
And for something from a Different Company:
Fables
Jack of Fables