I'm with 3. Never had any problems with them except occasional poor signal when I'm out in the boonies. I expect you get that with them all but I think O2 are supposed to have the best coverage. 3 give you a bonus thing as well where you get extra calltime etc the more calls and texts you recieve on your mobile.
Aint phones complicated! I can watch telly on my phone. Never tried it, I barely get the chance to watch telly on my telly.
Dave