Depending on level and class, I'd have to give it to engineer, this coming from a guy who mainly uses my com and op...

With the right spec, an engineer can pretty much guarantee a win if skills are identical in pvp...

Suppression will need a serious nerf, or the ability to stun to heal, pain and load up dots while pain stunned, then just run away while emoting lol will make one on one pvp pointless for other classes.