For light-duty stuff I have been amazed with the quality of my Black and Decker / Craftsman "3 in 1" tool.
It's a cordless Drill / Sander / Jigsaw. I haven't really used the sander for anything, but the drill and jigsaw work great. I got it a year ago for $99 and don't regret it at all. Ironically I bought it fully intending to be disgusted with it and return it - but I really like the thing for any kind of small/medium project.
It's a power unit with attachable heads that change its function. You snap off the drill and snap on the saw. I swear, I thought it would be junk too - but it's definitely a decent piece of gear. Also in all honesty it's a great "starter tool" in that you can use it and figure out what it's good for and then buy more $$$ tools as you see fit. Also, if you aren't super-hardcore, keep in mind that something like this can be useful to start, and later if you think you need better cordless (or corded, sometimes nothing beats the torque of 110v) tools, things like an extra cordless screwdriver ALWAYS come in handy. For instance, if you're drilling pilot holes and then screwing things together, it's great to have two cordless drill-drivers handy - one with a drill bit loaded, the other with a screwdriver bit.
Dremels have very specific things that they are very good at. But outside of those things (which I never seem to really need) they're mostly worthless. For house-size projects, I'd steer clear of them.
As for you get what you pay for: stay near the middle of the price range on tools and you usually do okay. Don't buy the cheapest and you probably don't need the most expensive.