Hands down, the M-14, I'm a big fan of the old-school guns like the M-1 Garand and the M-1 Carbine(I have one under my bed). It's just so satisfying to get a headshot with it too. Plus no complains about you being cheap. It also uses the same ammunition as the M-60, R-700, M-40, M-21, and the G-3 which means if anyone is using one of these weapons, you can pick up their ammo.