Mushroom croustades. This isn't the exact recipe I use, but close enough:
http://laurasbestrecipes.com/2009/02/mushroom-croustades/. I just use the frozen mini phyllo cups instead of making my own cups. Really really easy when using the phyllo cups, and they are always a huge hit.
Another go-to is pizza bread. Mozz and pepperoni is the best, but you could do spinach and sausage, or any typical pizza combo really. Buy a bag of refrigerated pizza dough (I use Trader Joe's), stretch into a large rectangle (about the size of a big cookie sheet), top with cheese and pepperoni, then roll up (from the long side of the rectangle to make a long roll, not short). Tuck the ends under and press to seal. Brush with egg wash and put on a greased foil lined cookie sheet. Bake at something like 350-400 until golden. Let sit for a bit, then cut into slices (diagonal are pretty). Always goes over really well.