As stated by Prodigy, they're not bad, just not great.
The very sharp Cyan contrast ruins the whole avatar. The KH default style is bright. Try to use dark colors to keep the canvas seperated.
The color combination is good, just the font isn't. Looks basic Arial, Verdana, Tahoma but vertically. Try to use your fantasy a bit more.
The avatar looks like a screenshot from a screenshotted magazine article. There's a minimum to none definition, except the black lines which seperates the semi Cyan and the render itself.
I personally don't like the combination of pure white and flash red. It kills my eyes for sure. Darken that red and use a border to hide the pinky/white areas.
This is a major color overhaulin' - Seems like the colors just exploded and randomly picked a spot. The colors are too dynamic, watch that.
Pretty decent, just don't like the blue paintball shots x] - Use a border to define it's canvas.
The render is awesome, I'll give ya that. But the whole styles doesn't fit at all. You use rectangle lines, which doesn't fit.
You'll doin' great so far. Keep learning! :]
http://a.imageshack.us/img401/6039/hitsugayaavatar1.jpg