I'm a sig maker myself, though not a very brilliant one, as I've only started a couple of months ago, but I thought I would like to give some comments on the nine signatures... just positive criticism, so you can improve on your sig making skills, and I can improve on my criticising skills and knwo what to look for in my own sigs and what to improve and avoid and learn.
1) It's pretty good, I like it very much, but it wouldn't actually work on a dark background, especially black because the white would contrast with it a bit too much and it will probably blind (well, not blind, but stands out a lot) people that look at it on the forums.
2) It like this one too... there's really nothing wrong with it apart from having the same problem as number one sig.
3) No comment. That one's very good.... maybe change the text font or size a little? I can read it, and I don't have glasses, but that doesn't mean everyone can read it too... good job, well done!!!
4) No comment. This one's really good, though the graphics not to my taste... but it's just my personal opinion.

Everyone can have a say at how they feel about it.
5) Very good... no comment either. Just the text, maybe.... .....
6) This one is the one that actually caught my eye and made my want to reply... firstly, that is way too bright, especially if you were to use it in a black and dark coloured forum. You'll have no problem blinding people, like you nearly did with it here on me... I think you saturarized your colours a teeny weeny bit too much. Try making it softer and maybe more natural... Not artificial like what you've done with it.
7) That ones good. I'm not concerned about the bright blue bit in the middle at all... It fits in with the rest of the graphics... Just change the size of the text a bit bigger than it is now... That's my only concern...
***This is for the first poster of the thread.