I've had this in a couple of Greek restaurants, and have loved it totally each time. Last year, it was my birthday lunch when I went to My Big Fat Greek Restaurant.
Basically, I used a recipe from the Food Network Web site. It's not as custard creamy as other moussaka dishes I've had, but it's pretty dang tasty, and I'd make it again! Oh man--just writing about it and loading photos up makes me wish I had a dish of it right now. I think this is a dish that would make an eggplant hater into a lover, and aside from the bechamel sauce/custard ... it's healthy. It's pretty easy to make, too, though some might be put off by the multiple steps (prep the eggplant, make the sauce, assemble the dish). It's worth it!