Warthog gunner class:
Primary weapon: Dmr
Secondary: Plasma pistol
Grenades: Plasma grenades
Armor ability: Camo or thusterpack (personal preference)
Tactical package: Shielding
Support package: Gunner
Explanation: This is a very specific class for big team battle games or vehicle heavy objective games. It greatly augments your ability to be a better gunner in the warthog specifically, it's also a really awesome alternative to use over wheelman package when you're in a mantis, as the shields will recover much faster, actually making a difference with the super slow regenerating mantis shields along with a longer turret firing time on its main arm. Shielding also helps complement your driver as you shields be back instantaneously allowing you to get back into the fray without worrying your gunners shields aren't all the way back. The DMR and plasma based secondaries are for when you aren't in a turret, warthog gun or mantis to deal with enemy players and vehicular threats.
All Rounder Vehicle class
Primary weapon: Dmr
Secondary weapon: Plasma pistol
Grenades: plasma grenades
Armor ability: Thruster pack, jet pack (for faster access to things like the banshee on certain maps) Active camo.
Tactical Package: Wheelman
Support Package: Explosives
This is a little known secret to make you MUCH tougher in a vehicle. Explosives reduces the damage you take from explosions, and this carries over to a vehicle you're piloting. Getting stuck by grenades will still be problematic, but area of effect explosions do much less damage to the structural integrity of your hog. Wheelman is self explanitory, as it is pretty much a requirement to anyone who seriously wants to utilize vehicles.