I'm looking at laptops, but I'm not really worried about size and weight. This machine's going to basically live at home, move room to room occasionally, but that's about it - think more "desktop replacement" than "ultra-mobile".
I took this approach with my last PC, and now consider it a mistake. By going for a laptop, I found I had to compromise on usefulness (and especially as time went on and it wasn't practical to upgrade), while in order to get a big enough screen and keypad to be comfortable as a desktop replacement, I found I was compromising so much on weight and battery life that it performed poorly on those occasions when I did go mobile with it.
Bottom line, if I were doing it again, I think I'd be inclined to go for a much smaller and lighter laptop for travelling, and pick up a 'proper' desktop machine for use at home.
YMMV, of course.
I am not really a power-user. Office applications, web browsing, and a little bit of media and game playing.
Sounds like pretty much any modern computer should be able to meet your needs. I would guess that the major question is over screen size/resolution, since I've found that to be the #2 issue in how comfortable I am with a given PC. (#1 is speed, but that seems to be tied to physical memory, which is quite cheap, and easy to upgrade.)
I'm more interested in reliability and good customer support than cutting edge performance.
I haven't had any notable experience with customer support from any supplier, so can't really help here. I've found that if I take care of my PC (good anti-virus, regular scans, regular backups), it takes good care of me. But I've been extremely lucky - only one significant issue in 5 years (running Vista, no less), and that happened a month
after I started doing regular backups.