What's weird is if I really get a good laugh out of it, I don't think I ever say "lol". If I grin or chuckle a bit, I may give an "LOL". However, if something is very funny, and it warrants a conversation, I'll probably say something like "Wow. That was awesome" on a youtube video or I'll give another quip. If I am going to let them know I laughed, I'll occasionally spell it out, like I did in one recent topic on Gamefaqs. I actually said "I can't stop laughing" when I was actually taken over by incessant laughter. It's a rare thing, but if I do laugh at something, most likely I won't say so, unless it is in-game or something like that. I don't know, I'm sort of random about it.

An example of something that makes me laugh every time: my sig. In the thread it occurred, I responded with
"Oh god... thank you wolf. I absolutely cracked up when I read that.  Every time I reread it, I laugh just as much.  Epic one-liner."  
Didn't say "lol" at all, even though I definitely did.
I miss Wolf XD