IBM are my favorites. I'm currently buying Gateways at work. (Why not IBM if they're my favorite? I meant the
computers are my favorite. Their sales force is indifferent and pricing is erratic.) A lot of people swear by Dells, but their customer service has been getting hammered lately; this may or may not be anecdotal, because it's certainly true that any of these outfits can make a lemon on any given day.) A lot of people like Toshibas, but given that I currently own
nine of these, I'm not favorably inclined to the brand at the moment.
Bottom line: with competition increasing and hardware margins shrinking to almost nothing, there's no manufacturer whose products are so good that I'd recommend them without reservation. At least, not to somebody I liked.
And oh, it depends on what you want to do with it whether Mac (in)compatibility is a problem.