I really dig Muddy Waters! I don't think of Pittsburgh as a destination for fresh seafood, but Muddy Waters is excellent. I am a fan of Blue Point Oysters, and during happy hour they are only $1! They also have a drink special I believe - we typically will get some champagne to enjoy with our oysters as well.
I love going with a small group, because I get to try everything! I love their cornbread and fried green tomatoes as apps. I like the po boy and lobster roll, but my favorite thing to get is whatever fresh fish special they have that day.
I keep coming back here because the food is fresh and delicious, the atmosphere is cool, and the servers are kind and knowledgeable.