For extreme long range, I use a silenced .50 cal with long range recon scope. Second sniper I carry around, is a Combat Rifle chambered for .308 with silencer, and "magic" ability of double damage to foes at full health with short range scope. Makes for a fine "close-quarter" rifle that is precise (one shot, one kill when undetected)
I have a lot of perks supporting rifles and sneak attacks, since I am not bothered with settlements, so lot of "free" points. Full Rifleman, Full Ninja, 4 point sneak, 2 perk sandman, full lone wanderer and full bloody mess. Needless to say, I lay waste to anything when undetected, no exceptions. Staying undetected is a big part of my damage, so I don't use energy weapons, which gives away more info about my whereabouts than I like.
Closequarter weapons is a silenced combat rifle, modified for close quarters, that fires two shots at once, and a silenced combat shotgun with double damage on crits.