Michelle said:
I know I am going to sound like a weirdo for this

, but I don't like addons that change a web page's design.
Well, I think that depends on the point of view. I am a programmer and like simple, clear structurised sites without too much fluff around them. For me, it's about content, not looks. It's about a fast way to find content, not a good-looking one. For example, I like this website:
http://ubcd4win.com/ It's nice, simple and has much content. But I hate a website like this:
http://www.macscreensavers.com/macindex.html (first one I found, could find probably much worse). It's artsy and so on, but it hurts the eyes, has way too small fonts, content is hidden more than it needs to be and so on.
But on the other hand, I'm also the type of person that prefers to use "Win+R -> edit -> enter" over clicking through the various start menu options (or for that matter, alt-f2 -> gedit -> enter in ubuntu) so I may not count