Uncanny X-Men (This book is terrible. Drop it) X-Men (Brian Wood is coming aboard soon, give him a shot)
Wolverine and the X-Men (Best X-Book on the stands)
Uncanny X-Force (was 2nd best X-book on the stands, now it's 3rd)
Avengers (Bendis Avengers suck. Drop it)
Secret Avengers (This book is going nowhere. Drop it)
New Avengers (Ugh, Bendis Avengers. Drop it)
Mighty Thor (Fraction has lost it. Drop it) Journey Into Mystery (I hear great stuff about this)
Avenging Spider-Man (worthless. Drop it)
Incredible Hulk (Terrible book. Drop it) Hulk (I hear good stuff)
Wolverine (Loeb is about to come back. Drop it after Bunn) Captain Marvel
DC Wonder Woman (I didn't care for it, but others love it)
Batman (DON'T EVEN THINK ABOUT DROPPING THIS!)
Batman and Robin (this book is easily as good as Batman)
Batman Incorporated (if you didn't read the first volume, don't get this)
Green Lantern (it's been fun up until the Indigo Tribe, not sure why I hate them so much) Green Lantern Corps (better than Green Lantern)
Image Saga (this book is a lot of fun)
I would also recommend you check out New Mutants, Atomic Robo, Invincible, and Nightwing.
Only buy the comics you really look forward to reading each month. Don't buy the comics you're only buying out of habit.
Came here to say this.
If you are not sure which books you are only buying out of habit, try this experiment: Let a few issues of each book pile up for a few weeks/months/whatever their publishing schedule is. If when you finally read the book you don't really feel like you have missed all that much, then you are probably reading it out of habit. Drop the book and/or buy it when it is collected into a TPB.