Always point-buy, if I'm given the option.
My problem is that I always roll one of three things:
1) Insanely overpowered stats, which I worry will cause other players to resent me,so I feel guilty;
2) Insanely underpowered stats, so bad that the DM goes out of his or her way to fix them for me, so I feel guilty;
3) Literally exactly on the line of "well this technically passes muster..." (e.g. in 3.5e, you have at least a 14 in one stat and at least a net +1 modifier before racial stats), leaving me frustrated and feeling a bit cheated.
There's a reason I call it "ability roulette." I really, really don't like rolling for stats. Because the odds are pretty good that at least one person in a five-man group will end up with either crap-awful or insanely-high stats, and that's an un-fun result for me. If I could have a reasonable assurance that everyone would get similarly decent stats (e.g. "everyone rolls, but you can choose to use any set rolled by the group"), it wouldn't bother me nearly as much.
Arrays are kind of a middle-of-the-road option for me. They're neither good nor bad, since there's no ambiguity.