Let me start by saying this is all personal opinion and should not be taken as anything more.
My favorite cap I have used to date is my Chadbroglass Terp Trunk. I love the feel, function, and durability most on this cap out of any i have ever used.
Second is my randallglass flavor cap. very similar function to the terp trunk but it only works on xl bangers.
And last is the gordoscintific RipTide Cap. This one is great for the fact that it spins oil without you having to spin the cap and comes in very handy!
Sorry for the lack of energy, i Was just not feeling it this morning.