Since I don't have much guns unlocked yet, at least from what I have at the moment
SCAR-H - Due to the AK nerf, I have given SCAR-H a new perspective. And the fact that I have issues in playing in US servers or matchmaking servers (I HAVE to kill enemy in one short burst) high damage output is a life saver.
LoL PDW - Nothing much to say. Should have left only DMR as all kit and removed carbines from all kit.
LSAT - Laser accurate if used correctly. Long range suppression/kill shots are awesome.
M40 - Despite CS being more versatile, the distance I usually engage targets with usually is better suited with M40 scope. Mil dot helps a lot since I don't always carry around PLD to gauge accurate distance. And switching long and short distance targets with zeroed scope is just nightmare. So, its just scope preference really. I still HATE Prussian 7x... stemming way back from BC2 and on. LoL
ACW - Its just weapon to go to when you want to win the face to face engagement, if you are not assault class. I think most people will agree with me on this one. Unless later unlocks are better. I heard G36 SUCKS, which saddens me quite a lot.
870 - If beta stats are still the same. But I don't really use shotgun, so I will see it being unlocked later down the line.
XM25 - Yes, I'm putting this as separate weapon. Its my #2 weapon of choice in overall stats. LoL. Though, ammo replenish seems to be nerfed greatly compared to beta, so it take a long while to get it back.