For a seafood restaurant in Anchorage, most people will say "Simon and Seaforts" which is located in the downtown area
Simon and Seaforts
http://www.r-u-i.com/sim/
http://www.r-u-i.com/sim/menu.php
420 L St
Anchorage, AK 99501
(907) 274-3502
The above is a little spendy and my place that is reasonable is Seafood Galley. It also has great prime rib and don't leave out their salad bar.
My recommendation for seafood in Anchortown is
Sea Galley Restaurant
http://www.seagalleyalaska.com
4101 Credit Union Dr
Anchorage
(907) 563-3520
chow
Moderator Note: Added direct link to SImon's on R-U-I site, and added menu link.