Well, my thoughts about signatures then.
I prefer small 1 or 2 text lines, or no signature at all.
The text should be something funny (or at least you think is funny), say something about yourself or just quote someone.
But, if you must have a picture in your signature, make it something that does not annoy everybody.
The one from Siege is a good example. It is there, but it doesn't disturb you while reading messages. Why? Well, it's small and only has text in it.
I made some examples to illustrate my point:
This sig blends in with the pages, but you can still use it to tell everybody to go to your website/webshop or place other text in it.
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Let's say Hans Klok would be my favourite performer of all time. That is something you all should know and be reminded of every time i make a post

. This one is also small, but because of the colors it doesn't blend in and stands out too much. This is distracting while reading the messages.
A sig like this get
very annoying
when someone makes a lot of
one line comments in a row
as you can see in this example
A sig like this is a big no to me.
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A sig like this
needs no comment at all. Get rid of it! It doesn't tell anything personally about you, just write -I like Hans Klok!- as a sig, it's the same. It's just to big for the page. And when you only write a 1 line comment your sig is 10 times bigger than your message (then please don't bother posting at all... unless you get cheap thrills of having a lot of post on the boards)
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Oh well, and one more brilliant signature you should be proud of
Look

this sig will make everybody jealous of me! It has my favourite performer in it, as well as some magical props and my name is also in it!!! Jay for me. With these randomly put together magical items with no personal meaning to me it's the perfect sig for a magic site.
When i see a sig like this, i just think "again someone who is very happy to have found out how photoshop works and now everybody must see his master photoshop skills". And the next thing you know they start offering their services as signature maker to everybody here who don't like sigs like this anyway.
Ok, that's just my thought about sigs. And a small explanation about mine so you can understand it:
It's just part of the lyrics from the song 'Hey jealousy' from the Gin Blossoms, but also because i have the feeling people sometimes expect too much from me when i make something for them, and i am afraid they might be disappointed with the final result...