I have a Black & Decker RTX Type 1 (you can't find them any more, it's the variable speed one) that is the best of all my rotary tools ever period.
I also have and like the Craftsman 12v (if you are considering it, get the Milwaukee it's the same thing but you can use the batteries on more tools), the Dremel 4000, a Mastercraft $30 affair from Costco, and I had one of another brand that recently died, can't remember which.
You can get all of them now except my favorite B&D. but of what's out now, get the Dremel 4000 and get the most expensive kit you can afford because even if you don't want this or that accessory, you will get more of your money's worth with the bigger kits. It's not the accessories you really care about, it's the attachments that screw on to them that are overpriced outside the kits.
The Costco one is very solid for the money, but it's obvious when you're grinding, using a buffer or wire wheel, the Dremel is just a better tool. If you are willing to do the comparisons, the Craftsman rotary tools are rebranded Dremels. I don't think they have one that is exactly the 4000 though, they do have a 3000 equivalent for decent price on sale. I have used the Proxxon one in a store but not anything heavy duty. I would still go with the Dremel 4000.
I would recommend if you want a battery one, get that as your secondary or if you have specific things to do away from power. You won't get enough time on one battery to finish hardly anything.
