I made a BBQ area on the last house. Roof w lights, bench for sitting/storing spare propane tanks, bar/counter to sit stuff on. The roof with lights was the best part of the whole thing. Didn't need to cover the bbq (or get a frozen cover off it) and could see what was happening. I would definitely make the roof lower next time. I had it 8' to the bottom of the beam and the ceiling about 8" above that. I was happy with the design but I would drop bottom of beam to 6'6" or so to provide more weather protection.
I'm slowly acquiring parts for an outdoor kitchen for the current house. I don't really love the idea but others do. It will probably have bbq, burners, small counter, sink, garbage drawer, misc drawer and bar fridge.
Edit:
I guess I didnt include a picture of the best part. I made crown molding that would hide an led strip and allow it to shine up across the ceiling. I switched the 12V to that strip so I could turn it on when using the bbq but if I killed the railing lights, it would go out too.