I've been trying to unlock attachments for all guns so I haven't used many good ones in awhile. ACE 52 would likely be my goto. Hard to go wrong in the Assault class ... had some great rounds with the FAMAS, ACE 23, L86.
I use the Angled grip a lot, maybe too much, but I notice a difference on many guns. For instance, recently I've been raging using the M16A4 because it is simply terrible out of the box; the recoil sends you to the moon. Then I unlocked the Angled grip and it turned into a serviceable assault rifle.
What I like to do on a map is very map dependent but on many maps I love to go A/T mines and M2 SLAMS and hold the objective closest to their deployment, where all of those delicious vehicles are coming out to play.![]()