We went to Niko's in Brookline tonight. It was a nice surprise--good food, friendly people, and decent prices. The grape leaves were very nice, with a light cream sauce on top of them, and the lemon chicken soup was delicious.
Overall, I still think I like Greek Corner a little better, but not by much. I'm still looking for that one Greek restaurant that blows me away, though (and doesn't cost too much); perhaps I'll head up to Lowell to try a couple of the ones up there. Athenian Corner is the one to try in Lowell?