Before its conclusion I would have said Uncanny X-Men Vol. 2. Now I would have to go with X-Treme X-Men as it's the only X-title that I'm currently reading. Aside from that, I'm patiently waiting for Cable and X-Force and Uncanny X-Men Vol. 3. I would have counted All-New X-Men but I will be dropping that title once Uncanny X-Men starts up again.