So I've started getting into the signature scene myself, the first one I did was the GTA IV one that you've been seeing in my sig for the past couple of weeks. Of course that was nothing but a cropped screenshot and some animated text.
Here are three more to show:
J Dilla:
I love this one, took me a while. This is my only new animated one.

Edit: On the right, the lighting is sharp and needs blending; it's not supposed to look like that. I think it happened when I flattened the image so that it could be in .gif format.
Edit 2: Tried fixing it, dunno if I can, whenever I upload it to photobucket it gets like that. The image isn't like that when I open it.
RZA:
Simple. My second one after the GTA sig, so doing the background and such was new to me.

TV on the Radio:
This was a quicky, I found the image on the web, gave it a border, and rendered the text off of their album cover. The band was on this background, which I thought was pretty wild so I left it.