Keep an eye RyanAir! I just found a good deal with them. They may have crap service, and try to slam you with fees, but sometimes you can catch great deals! Swing by Constantinople sometime, totally worth it for the Hagia Sofia alone. Topkapi palace is pretty cool, and has the church of Hagia Irene where the First Council of Constantinople was held. Plenty of cool spice markets and the like too.
I'll definitely plan on visiting Pella and Phillip II! Gotta start saving.
I'm also learning to speak Greek. It's hard, but fun to learn the roots of a lot of English words. People often think I'm from England, as they don't expect Americans so often, unless you're in a tourist area.