2 hours should be fine. I usually get there an hour early and i'm sitting for 40+ minutes of that at my gate. I fly out of Baltimore-Washington Int...which is a pretty popular airport considering it's right by the capital. I've never had a problem other than when the machine wasnt working for my e-ticket (the system froze). Every once in a while I'm the one who has to go through the extra security..but that only takes 5 minutes or less.

2 hours should be more than ok. Have a safe flight!