I second Blackfish for seafood. (BYOB) Savona in Gulph Mills is also very close by. The dover sole is their signature dish but you will pay handsomely for it. A very sophisticated and upscale place. In Manayunk on Main Street is Jake's (a particular favorite of mine)
Viggiano's in Conshy is a nice family-run BYOB - I've had numerous good meals, including my rehearsal dinner and a bridal shower... although I think they've down-sized their dining room so I don't know if that means changes in the menu?
Well, after reading the following post, it seems as though Viggiano's has gone down the tubes (I hadn't been in about 2 years) but check the post for other possibilites... http://www.chowhound.com/topics/357542