I'd have to say Sniper because they just don't have the cool feel to them that they have in games like Delta Force and Battlefield.
Then General Vee... Imperial Officer I mean, because he's just so messed up he's a joke. He's not even an Officer (as most people think of them- think Moffs and Admirals and anyone in grey who shouts "Rebel Scum!", not General Veers) for a start and his primary weapon is a GEONOSIAN SONIC PISTOL which completely contradicts the long established Imperial hatred of Aliens. And it sucks. Commando pistol or the Precision Pistol would have been nicer. The Mortar Launcher isn't anything to advertise. Rage isn't all the rage and Recon Droids aren't unique to him.
Then the Jet Trooper. Overpowered in SWBF1? Yes. Now? He's just a free kill much of the time. It's not his weapon, it's his Jetpack, from which he derives his name. 5 seconds of slow flight. What's the point? Giving him 10 or 15 secs flight time isn't going to overpower him. He's weak and has a pretty poor weapon, high target and only 4 of him at once!
Surprisingly, I don't mind the Droideka.
Battlefront II common classes: Bothan Spy, Imperial Officer, Clone Commander or the Droid Engineer. Without points an Engineer or Vanguard.