It just depends on your preference, but in PVE I find all the classes pretty balanced. Yes, there are easier class for solo leveling. I know Agent, Shadow and Scoundrel are easier, because they have stealth and longer CCs. However, with the knight I have found I don't need Stealth, CCs or even a healer. I just kill the bad guy before he kills me.
You will not get any sympathy from me. I solo leveled sawbones for my first toon with no knowledge of rotation, equipment and a kill everything mentality. I died out in every boss fight, had to farm credits just to pay for repair bills. I was just too stubborn or stupid to quit.