Ah, another collection to critique. *Cracks Knuckles*
1st, the Border on the last two, is way too thick and the 3rd, with the gradient border is pretty bad, The heavy brushing on all but the bar ruins the actual flow of the sigs, text color/font/ effect is bad, and could use improvement, such as the removal of the bevel on the 2nd, changing color on the 3rd one, and the over blurred turd color on the 4th has to go. The font on all of them is not the best choice, I suggest a cleaner font, Like Arial Black, (with formatting and tweaking), or Arial (with format and tweaking). The animation shouldn't go against the flow, but with it. if you were going for a rain effect, have sections interact with points on the render, and for a film grain effect, have it more incremental, instead of a constant. Finally, the bar. Lessen the scanlines, and try the Xbox 360 font itself, in Uppercase, with relevant colors.
Ratings:
The XBox 360 Elite Userbar; 7/10
Halo sig; 6/10
1st Bleach sig; 7/10
2nd Bleach sig; 6/10.
You have room to improve on all of them, keep at it.