If you are looking for ethnic type dishes (or something out of the norm), I would recommend Tropika on Centre Street. The restaurant's signature dish is the K.L crab (short for Kuala Lumpur) which is deep fried & blanketed with crushed dried shrimp, served on its shell.
You can also try Monty's Crab Shack near McKnight Blvd or Bookers BBQ & Crab Shack on 3rd St SE. Both these places serve steamed/ pan fried crab legs.
If you're looking for fresh crab to prepare at home, I've found that T&T is the one of the best. The turnover is really high so the crabs never sit around for too long. During the weekdays they have specials all the time as well. They only have dungeness crab and sometimes blue crabs fresh.
I haven't found any restaurants that have crab legs prepared differently than other places. I prefer to cook the crab legs at home. I buy them frozen from North Sea Fish Market in Willow Park. I asked the owner one day if he had any tricks, and he gave me one. He said that when you put the water in the pot, season it. So I put butter, bay leaves, salt, cayenne pepper and whatever else I have on hand that would be flavourful. Boil it together and then steam the crab. That way you get a little bit of flavor in them.
Also, if you don't feel like just plain melted butter; a good change is lemongrass butter:
1/2 cup butter, melted (125ml)
2 cloves garlic, chopped
The juice of 1 lemon
3 tbsp of white wine (45ml)
1 tsp hot pepper flakes (5ml)
1 stalk lemon grass, peeled and chopped
1 tbsp olive oil (15ml)
Splash of white wine
Just simmer it all together in a pan until cooked.