PicMonkey

PicMonkey - I found this site to be very helpful and easy to use. My only compliant is that there are a lot of things you can't do without paying for it.
Pixlr - This site was for the most part easy to use, but I will probably not use it again because it is a little complicated to figure out.
iPiccy - This is without a doubt my favorite site that I used. It is not only easiest to use out of all of the sites, but it is completely free.
BeFunky -  This website was for the most part pretty good. I have no complaints, but for some reason, I didn't like it very much.
piZap - This site was fine, but there was nothing that set it apart from the other sites that I used.
LunaPic - I found myself being overwhelmed by the amount of different effects there were, and they didn't look very professional.
Favorite: iPiccy
Least Favorite: LunaPic