DSL is fine... however, usually it is slower than cable... get FIOS. the end.
We have 1.5mbps DSL, and while it usually works fine for gaming, it is rather slow, and has periods where we get some real slowdowns. Would rather have cable, and would much rather have FIOS.
Either way though, if your comcast is out most of the time, I would first talk to comcast and see if theres a reason for it, otherwise, the 3mbps DSL should serve you fine.