My favorite Javik moment isn't from him but from Wrex if he's alive and you take Javik with you to Sur'Kesh..
Javik: [Something intense and tactical] Wrex; "Who's THAT?" Shep: *pause* "...he's a Prothean." Wrex: *blank stare and shakes head* "I can never tell if the Normandy is a warship or a traveling freak show."
It's not that funny written out, but the timing is perfect in the scene