I am sticking by IBM on this one. I trust them to make a better computer than most other companies for one reason - they build computers right. If I didnt build my own systems, I would probably buy IBM systems. Their laptops are incredible, but it all comes down to what you use it for. If you are a gamer, i would reccamend the Dell because of their great gaming 'tops, although most (all?) of them have P4s in them, which consume a lot of power. If you are wanting to use a system for average use, or actual "Work", then I would definatly go for the IBM. They've been making computers longer than most, if not all companies out there. Heck, they were the first to create the... (trumpets sounding) ...PC! Theyre tried and true, and all though Dells are also wonderful systems, I would not overlook the overlooked.
Off Topic: Damnit i wish Micron still built systems... I wouldnt mind a nice workstation right now...