Chaya is a lot of fun; definitely the best place in Pittsburgh to get adventurous with sushi. I've had better sushi for sure, but not around these parts. Weirdly, one of my favorite things there is the fried chicken that accompanies every dinner. Its golden-fried goodness is the perfect start to an otherwise raw meal.
The place is small, so try to go early for dinner. I wouldn't go in a group larger than four, either, or you might wait for a very long time.