I wholeheartedly second the random orbital votes. I now have a six inch hook-and-loop (velcro) DeWalt and a five inch hook and loop Porter Cable. (The smaller PC is for detail work and tight areas.) With the hook and loop, you can easily re-use any sandpaper that isn't worn out. I've been totally happy with both sanders.

I also highly recommend spending an extra $4 to buy the "gum eraser" sticks that are used to un-clog sandpaper. It makes the finer grit sheets last MUCH longer.

(One additional point...I found the extra expense of a variable speed sander was very helpful when doing finishing work. You can slow things down and eliminate heat build-up.)