Not to sound like uber-queen-bitch-of-the-universe, but I don't really like any of them. #1 looks good pretty much because the background is something someone else painted. #2 is the one I voted for because it's probably "blended" better than the rest, but the choice to lighten the entire sig just..well, it kinda looks bad. I would've added more contrast instead. #3 has weird colour issues, but a pretty cool render. I'd change the border, too. #4 is kind of cool because it looks different and it looks like they combined a whole bunch of stuff to make that sig. The white border, the text, and the awkward size of it are what kinda put me off though.
I didn't actually take the time to read the text on any of these signatures (cept 2, since it has none) because all of them suffer from a case of bad font choice or bad font colour.
Sorry if any of that came off as harsh. I just think SOTW had an off-week. Maybe I should stop being an overcritical *** and submit a sig as well. >_>