Up until recently would have been the Exocet V1, but now it's the Heir. A Billet Box and an Heir would be my desert island device for sure - be useful for breaking open shellfish too
For me it has to be the Insider closely followed by the Exocet v1, i do quite like the Vape Snail also. My goto vape is the Nautilus bridge and coils, love em.
For me, Steam Tuners Insider MTL. Runner up is the vapesnail. I've bought many bridges, but insider MTL is the one I return to for its Kayfun-like vape.