The first thing that comes to mind is.. "I wanna make awesome avatars like those!" but I'm sure that has nothing to do with anything.
I can't make good avatars, so seeing the five above is making me jealous. Lol You really did a good job. If you don't mind, can you give me a few tips for making avatars? I can make sigs, but I have trouble working on such small canvases that avatars require.
As for your sigs. There are only about two I don't like. The rest are amazing. I believe I like your current set the best. It has great color, and depth. The lighting is a little bit shaky, but not something I'd notice without close inspection because everything else kind of distracts me. XD It's that pretty.