Woodtick, I gotta disagree with you. I know most of my friends in construction use DeWalt. However, they are beginning to look at other brands as well.
Asker: If you want to take a chance and not spend a lot of money at first, I would get to a Sams and buy their $49.95 drill driver set. 24v, two batteries a charger and a case. I bought one on a whim and have been using it almost exclusively with great results. Has two speeds and about 18 torque settings. I have found the batteries charge fast and last quite a while under load.
However, that said, I have not had it all that long so do not know about longevity. Makita, DeWalt, and some of the others are pretty expensive. DeWalt has a newer low profile or compact drill driver that creates a ton of torque, and is being used a lot by the guys I know. It is a bit lighter but that helps on over the head jobs.
Finally, I have used the upper scale side of Black and Decker for a long time and have few complaints. I would stay away from Sears--who knows where made, from what, and they don't lifetime their craftsman electricals altho they want you to think they are giving the same warranty as their socket and other non electric tools.