For fresh seafood head over to Cijin Island's seafood street, or try the locally recommend Lai Lai. It's the kind of place you go to eat good seafood, drink cheap beer (NT$70 a pint), and be loud like the locals. You can barbecue right at your table or just tell the staff how much you want to spend and they will arrange dishes for you. Be sure to tell them of anything you don't eat (like fish head, perhaps?).