It all depends on how you set up your character to be truthful. I'm playing as the assassin and have the whole bloodshed skill tree maxed with 4 points in the middle skill tree. Blood shed is your best chance for sneaking, and it also gives a good amount of health and allows you to dish out really high Melee attacks. The commando I made is going to go to the bottom of the Survival skill tree to have 2 turrets and also to the middle of the Guerilla skill tree for the rockets. Maya by what i've read in her skills are good in all Trees, if you want to be a medic, go with the middle one, if you wanna dish out massive damage, go for the other 2 by what i've seen. The Gunzerker is good in all his trees to, although he is like the Berserker were he is only good when you get him really high level, you will need to spend your points good, and if not, respec them. Also the link above going to "The Best Classes in Borderlands2" is a laugh, they are saying the Mechromancer is a total piece of crap even though none of the skills have even been shown besides a few, although in my opinion she will possibly be a good class to play as when she is released.