You can't really go wrong with the name brands... Just don't buy the truly asian shit from Harbor Freight.
QTF. Although HF power tools are sometimes decent (for the money), anything without a cord is guaranteed crap.
I was impressed with the quality of their current angle grinders. The one I got for like 20 bucks is as good as the Craftsman one I've had ten years or so that was probably like $80. Maybe better. They're both noisy as all hell, though.
Their drills are bad and their batteries are surely astoundingly terrible. Improvements in even cheap composite materials (read: plastic crap) have made stuff feel a lot better, but the guts have gotta be stupid-simple, brute-force kinda stuff. Another example of something worth the money would be their 3/4" air impacts. They're not GOOD, but they're stronger than any widely-available half-inch wrench, so they're good for, you know...breaking shit (seriously- crossthreaded lug nut removal tool).
Major brands built in China will STILL vary widely in quality, but it's usually pretty easy to group the contenders appropriately. Craftsman (lower end non-'professional'...though I think they write that on everything nowadays), Ryobi, ect standard consumer brands...well, usually work fine for consumer use. Dewalt, Makita, Milwaukee, ect usually work fine for professional use. And the lower end is close to the 'consumer' price range and IMO usually a worthwhile upgrade if you want it to last (also usually better triggers, chucks, and whatnot).
Preference among the better (but not crazy expensive) brands, to me, usually seems divided among mechanics preferring Makita and contractors preferring Dewalt. But those two seem to dominate in general.