The results are in:
M4A1 - 8
M16A4 - 4
SCAR-L - 7
CM901 - 4
Type 95 - 0
G36C - 6
ACR 6.8 - 14
MK14 - 5
AK-47 - 9
FAD - 5
The most used assault rifle of this forum: the ACR 6.8, with 14 votes.
The AK-47 and the M4A1 take the title of second-most used, with 9 votes, and third-most used, with 8 votes, respectively.
The Type 95 comes in dead last with no votes at all.
Thanks for the participation! Next poll: SMGs!
For damage up close and personal, I use the AK-47 with Kick and silencer or the CM901 with Kick and extended mags. For medium range and emergency hipfiring, I use the ACR with Dual Attachments (silencer and extended mags). For a more sniper-y map, like Outpost, I use the MK14 with Dual Attachments (silencer and hybrid sight).
I have leveled all assault rifles to 31 except for the M-16, FAD, and M4A1. Just haven't found them as useful.