What do you use to clean your guitars?

I'm in one of my "all I want to do is play guitar" phases and am about to restring all my guitars and figured I'd clean them too. I know there are plenty of products out there, but is there anything fancy you guys use?

I went to Guitar Center today....saw a Martin I've been eyeing for a while and it was on sale...I might be making a trip back this afternoon. I don't have a 6 string acoustic right now, only a 12, it sure was tempting. What is your go to guitar?