Well, out of the companies your list, Dell and Gateway probably have the best reputation. They're both pretty reliable, they have pretty good support, and they're just all around good computers and companies (even though Dell does have Steve in their commercials).

I have an HP and it's always worked great for me, but for some reason, their reputation is lower. The only issue I have with it is that the case is tiny and ther'es not much room for upgrades.

The old Compaq's used to suck, but maybe now that they're getting together with HP, they won't suck so bad. I wouldn't want to be one of the guinea pigs though, so I'd stay away from them.

I haven't heard anyone say anything nice or mean about IBM computers for years, so I can't help you with that one.