gas cap

What gas caps are people using? I have an 07 zx6 and I hate the stock gas cap the key gets jammed sometimes. I want just a black gas cap, a quick turn style but really haven't found much of anything out there. What are you guys using?

So idk if this is normal my 07 zx6 after riding until the tank gets hot and builds up some pressure inside when I shut it off and the engine isn't running I can hear fuel vapors coming from thr gas cap. Idk if the whole cap is bad or a seal inside there but then if I just open the gas cap and...