teh cattle rifel most of all...it is one of the start woepons sumtimes and it is powerful especially with headshots...then comes teh energy sword for excelent short ranged attacks usually better for sneak attacks...shotgun can beat energy sword by bulltrue or watever its called again (i havnt played in a while)
As cheap as it seems, I love the sniper rifle. Nothing is more fun to me in a game than hiding in a bush and sniping people. However, for close range combat I really like the Assault Rifle. It's simple, yet effective. Unload a clip, then smack them with your gun.
However, my favorite weapon to actually kill with is the flamethrower. As a pyro, I can't explain how amazing it feels to have someone fly out of the grav lift, into a bunch of flames, burnt to a crisp by the time he hits the floor.