Zigzag.

I was blocking traffic while checking my phone in game and the dude behind me was honking and then yelled out "I'm about to beep my pants!" and rammed me out of the way.

When you're in the middle of a HUGE shoot-out and one of the cops goes "cock sucker!", with the most feminine (GAYYYY) voice ever.
That cracks me up every time I hear it.

Walked by an obeses chick talking into her phone.She was saying" Ooooo yes,I'm a model,really slim and have worked for lots of agencys"

Also I love Floyd's comments after Trevor takes over the Vanilla Unicorn.
Wade.
I like walking around Grove Street as Trevor and taunting the Ballas. They sometimes say funny stuff like, "yo daddy's a dickhead". Or "Yo mama ain't sh!t."

I like when you chose Chef for a gunman in The Big Score(the Obvious Approach) when Michael picks him up Michael says "Are you ready to do something really crazy?" he replies "You mean crazier than working for Trevor Phillips"
Also I love Floyd's comments after Trevor takes over the Vanilla Unicorn.
http://kevan.org/brain.cgi?HuckleberryBeej.

"what if smoking lettuce could you get you high, but nobody knows because nobody has ever tried it!"

Dat sh!t was f#@ked up last night right?

"You beep beep ! I am going to beep you up when I get you, you beep beep ! You piece of beep beep !"
Oh wait, that was a message to me from another gamer after I blew him up with my tank
ant-mac