Boredom mostly.

It depends on the title I guess and if my friends are hanging in the thread or if it's my friend's thread. And sometimes I'm bored, want someone new to chat with, or just want to make some goldies.

I usually click topics I haven't read yet, like this one, and then post if I think of something to say. ;D

Works pretty well.

I look for any topics that either look like something I'd have an interest in or something relevant to my mood at the time.
Also, spelling is a big part of it.
I will almost never click a topic with poor spelling in its title.

Witty and interesting titles are what catch my eye. Or it might even be something which I can relate to or to which I can respond. :)

The fact that there are a ton of replies to a thread all on the topic of "Why do you click here?" made me click. Ironic isn't it?

I like funny, intresting and unusual titles.. I usually click the ones that people have comment on recently as well..

If it's alight hearted topic I tend to click it.
Debating gives me a headache.

Titles which I recognize or can relate to, usually catch my attention first.
After that, it's usually lighter topics and/or topics which sounds fun, be it with a joke or funny word. I also like recently updated threads, but that's not too important.

I try to stay away from titles with all caps and too many strange symbols and I very rarely, if ever, click a title because of the icon/emote/flag next to it.

Symbols and long titles certainly attract my eye, but they aren't what make me open threads. It's what's in the title itself. Was it something funny? Did it have something to do with my interests? Was someone asking a question that I have the answer to?

Interesting topics -nods-

The title; and I generally only read the first and last page.

The title. Very simply put, however they state it. It sound's more interesting, thus making me want to click on it to find out more.