Well, what is YOU, if you want something that "fits" you? Only you can figure that out for yourself. Tell us a little about yourself if you still want us to help you out. Maybe there's a quote or song lyrics out there that you really like. I have my entire VP collection in mine because I'm quite proud of it. I also have a quote that I really identify with, something that motivates me. A link to a few of your favorite websites is good too or maybe there's a cool video you like that you want others to see. Just remember that you have a character limit so make it count! Besides, who says you have to stick with one the entire time? You can change it because everyone changes a varying times anyway. I hope you find something!
Icons that match the siggy -- emotionally or appearance -- make great signatures. Or, as I call them, sets. A bright icon with red and orange and yellow colours don't go so well with blues and blacks. Put them with colours that match and your set will be very nice to look at.