Hitachi makes a very good cordless drill. A buddy of mine has a 14.4 and loves it, we were installing a kitchen together once and I used it quite a bit while we were there and I kind of liked it, but I'll have to wait till all of my others crap out before I get another.
From alot of carpenters I've been talking to lately they all swear by Panasonic. A good friend of mine who is in the concrete business caries a 12v Panasonic impact driver and a 18 volt panasonic drill in his truck. If you are just needing somethgin to drive screws and nails forget about a cordless drill and go with a cordless impact driver. His 12v impact driver will run circles around any 18 volt drill I have ever used (DeWalt, Milwaukee, Porter Cable, Craftsman etc). Plus Panasonic claims their batteries last longer, I can't back this up but I do know that Panasonic is one of the only cordless tool manufacturers using metal drive gears instead of plastic.