They don't fit to well with the backgrounds and the fonts aren't really working to good with the themes.Also your renders need to be better blended with your backgrounds. Backgrounds, need more pazaz they are quiet plain and dreary. I would suggest going tot he free section and getting some of the free tuts or do some more posting and buy one of the tuts out of the paid tutorial section. Also good-tutorials.com is a great place to find some tuts on photoshop.
Most of your sigs look like a bg with a render slapped on top. Work on your bgs alot, try to give them a more exciting look. Also work on coloring, all of your tags are one color, add in some more color, and you'll sigs will look alot better.
