I've got an old Bosch 12V (NiCad) drill/driver that has seen a lot of use/abuse and has never let me down, though the batteries are getting past their best (had it a few years). Very light and the clutch has good feel even though there are only five settings. This one's not made any more, but the current equivalent is about £80.
Also a Panasonic 15.6V (NiMH) drill/driver with 3.5AH batteries. This is a very nice piece of kit. It feels almost like sometihng you'd use on a factory assembly line - very precise (the chuck is very good - clicks positively as it is tightened, there are more torque settings covering a wide range of grunt, and it will grip the tiniest of drill bits). One fresh charge will drive well over 200 No.8x3" screws into softwood without piloting. Notice though that I said FRESH charge. The major flaw for this drill is that it refuses to hold charge for more than about a week. A full charge only takes about 45 mins. but having to charge it every time I use it (certainly feels that way) is a real pain.
So Recently I treated myself to an 18V Makita Li-Ion combi drill. Normally I'd avoid something this hefty like the plague. I'm not the strongest guy in the world and when I've used some older style 18V and 24V drills in the past, the sheer weight and bulk has been a killer (especially if you have to be working above head height for any length of time). But this Makita is VERY light for an 18V drill (about 1.7kg, virtually the same as my old Bosch 12V), it charges incredibly quickly (the charger is fan cooled!) and it holds charge far more effectively than the Panasonic. The battery pack give a decent working spell, though not quite as good as the Panasonic (when it's holding charge!). Rohm chuck is good quality. One thing I would say though is that the range of torque settings seems to cut off too soon (i.e. the clutch lets go too soon on heavy duty screwing (can I say that on here?!). When I first got the Makita, I thought it was a bit too lightweight because of this. Then I set it to 'drill' rather than 'screw' in desparation and promptly sent a No.12x3" screw straight through a piece of 4"x2" pine! It is a very powerful piece of kit - the clutch torque settings just tend to disguise the fact. The hammer drill isn't up to much (nowhere near as good as an SDS) but I guess it might get you out of a tight spot. I bought mine with two batteries for about £210, but I've seen exactly the same drill with a single battery for about £160 with one of the online retailers, and for that money it's a bargain.
Perhaps the best thing about the Makita is that when I give it some real grief (say drill ing a few deep holes with a 32mm spade bit) it smells exactly like my Scalextric handsets used to when I'd used them for about an hour. Those were the days.....
Hope this is of some use.