...Rotflol. (Rolling on the floor laughing out loud.) My favorite, but only because it's in Weird Al's White and Nerdy video.
NVM - Nevermind, obviously.
BRB - Be right Back
g2g - Got to go
<3 - Heart, I love you. Love, peace, whatever on that line.
On the whole, I rather detest internet slang. I feel it to be a disgrace to human language and grammar, and lacking in any linguistic integrity. It's hard to understand, and down right annoying.
Ex:
"Hello, I'm pleased to meet you. Would you like to be friends?"
Becomes:
"'SUP? Ur kool, letz b budz! XDDDDDD!"
I swear to god, one day I'm going to go on some ludicrous genocide against chatspeakers.
Read:
Urban Dictionary: chatspeak