The first power tool I ever bought was a Dewalt cordless drill. Dewalt are pretty much the leading power tool manufacturer around, fighting up there with the likes of Makita, Milwaukee, Hilti and Bosch for the top spot.
To be honest, the majority of my best tools are made by Dewalt and the reason I keep spending my hard earned money on their power tools is because they've never disappointed me in terms of power and reliability.
I've just bought a new Dewalt percussion drill and a battery drill driver for £150, that is a deal!! I don't know what kind of bartering is going on behind the scenes, but there are some ridiculously cheap deals on cordless and corded Dewalt tools especially if you buy two drills like I did.
(Sorry, getting back to the quality) Also, on the few occasions anything has gone wrong with them (usually my own fault for abusing or dropping them) I simply take them along to my local Dewalt dealership who repair the tool while I wait. Often that's for very little cost or for free, under warranty.
That to me is a massive selling point, getting tools repaired or serviced is as inconvenient as having your car breakdown on you - there's never a good time for it to happen and it generally costs time and money! Whilst I work within a 50-mile radius of my home, on the rare occasion a tool has broken on me I've never been far from a service center that stock the part and can repair the tool while I wait.
A normal drill/driver is a lightweight drill for light drilling jobs and most screw-driving. The majority of Dewalt cordless drills these days have all metal gearing, 3 speeds/gears, keyless chucks and several (often over 20) torque settings. You can buy a decent Dewalt cordless drill for around £200.
I've got a Dewalt DCF885 impact driver and it's great. Really light, really powerful and no more rounding off screws trying to bury screw heads in the timber. If you don't need a drill for everything this is an amazing screwdriver, your work mates will be jealous!