Most underutilized/overutilized weapons in your opinion.

[AThreatToYou]

Overused:
Snipers. I hate them. I hate snipers. I hate the good ones and the bad ones. Okay, maybe I don't really hate them, because I farm them in my Flash. But, consarn it! They keep on with their 1HK headshots and it is very unfun. Also keeping in mind that those snipers I farm in my Flash are REALLY doing jack squat for their Empire. They'd be better off as an engineer or medic.
Sundies that do anything but deploy as AMS. A good bangbus can have a real ball of a time, y'know? Only takes 3 guys.
Any of the 750+ RPM weapons seem overused. Yes, I most commonly die to them, but I also see a lot of allies carrying them in situations where they would be better off using a longer-ranged weapon.
NC faction entirely.

Underused:
AV 'Nades. I think that they are sticky or something. Throwing one of these along with a rocket in the back of an MBT will hurt, a Lightning it will kill, and its cheaper than C4. Also don't lose much compared to frag nades, but even I don't have these 'nades.
Vanu faction entirely.