I really enjoyed the lobster roll at Boardwalk Bakery (can't say definitively it's the best because I haven't tried all the other options at WDW). It was a generous portion of lobster meat and the mayo wasn't overpowering. I've also tried the lobster/shrimp/scallop roll at Hurricane Hanna's but I was not a fan of that - to me the lobster was undetectable.