IF/THEN/ELSE
Okay, I couldn't decide on this one myself, and there were lots of good suggestions all over the place, but I think we've got something simple, a modification of O RLY. It helps that the various forums that link here called that construction out as a good one.
HAI CAN HAS STDIO? I HAS A VAR GIMMEH VAR IZ VAR BIGGER THAN 10? YARLY BTW this is true VISIBLE "BIG NUMBER!" NOWAI BTW this is false VISIBLE "LITTLE NUMBER!" KTHX KTHXBYE
See IZ for more details on the conditional statement.
And let's open up BTW as the comment form. I'm not closing the door on ^^, but again, I want to minimize the amount of punctuation.