For what it is worth, I have the Actron CP9175. No frills to it. They have a simpler model that JUST showed you the code and allows you to clear it. I think that would be just as effective. In any case, the one I have is under $100 right now. I get to pull it out of the garage every couple months when I need to talk a car down off a ledge...

I also have a CarChip. It is able to read and clear codes, but it is such a pain to do so, that I can't recommend buying it for that reason. Actually, the only reason to get it might be covering your butt after an accident or a speeding ticket, I guess. I really don't use it anymore, but I still leave it plugged in.