A few that I've demo runs on that i liked. The tesla, vamo, evic. First off the evic was crazy at what you can do with the chip set in it, customizable firmware. Vamo a solid go to device got a great vape from it. Then the tesla was ok but great for the guy i borrowed it from. Ran all of them on a 2ohm coil in a aga t to get a feel of the vape from them. All 3 solid devices but the evic was my favorite due to the nerd factor of the plug and play software. Then if you have the money you can't go wrong with a provari or dna mod(if you can find one)