I can't say anything good or bad about Gateway.
I can say stay away from HP or Compact. I've had bad problems with both brands in the past that led to significant expenses or monetary losses for me. I find it ironic the two companies merged a few years back. They deserve each other.
I had a Sony that worked well for about 4-5 years before it died.
I now have had a Dell for about 2 1/2 years now. I had some issues back in Jan/Feb, but I messed with it for a while and the problems went away.
Other than that brief issue, it's been good to me.