Standard issue Starfleet type 3 phaser rifle. Comes with multiple power settings - you can warm up toast, or vaporize your target, or anything in between. No recoil, optical sight that includes targetting computer that will analyze in real time the environmental variables, distance to target, and provide the user with the correct firing solution.
Need to hunt for survival? Kill *and cook* your game at the same time with this baby.
Pinned down by enemy fire? Take away their cover and probably take them out in the process with a max power shot.
Need to capture an opponent alive? Stun their ass and send them to nappy times, so you can secure them without resistance.
Find yourself in a cave and in need to warm up, maybe dry out some wet clothing? no problemo! Just warm up a nice stack of rocks, so you don't need to build an oxygen-sucking fire, or give away your position with smoke.
About the only thing you'll really have a problem with are the Borg, since they have adapative shields. You only get a few shots before they adapt, then you better be able to change pulse frequencies or outrun them, else you become one with the Collective.