Has all of the best tech skills of the Engineer. He's better with Pistol and Sniper than Soldier, and just as good with Assault Rifle and Shotgun if given as a bonus. ME1 - Has Immunity, the best defense power in the game, so tanks as well as Soldier does. It's close between Infiltrator and Vanguard, but I think Infiltrator is the strongest. From my exp, Vanguard is so powerful that they are capable of killing Brutes and Banshees within seconds if you know how to connect charge, nova, biotic / tech burst. And their incendiary ammo have nice DOT + burn effect can combo with a lot of skill -> explosion.
It's very risky as you will have to expose yourself to enemies fight, but their biotic charge can instantly recover shield (to full strength if you choose that skill path), so fast cooldown + Nova combo = ownage.
Vanguard's close quarter fight is insanely fun. Most of the time you can eliminate all threats before they can even come close. It's all about tactic: knowing which enemy to take out first, carefully aim, good timing. Infiltrator is pretty deadly with tactical cloak and sniper head shot. Only from ME 2, with the dramatic change of gameplay that classes started showing their own pros and cons. Can't say much about ME 1 since imo, classes weren't that different back then. Though personally, I like Infiltrator and Vanguard best. Each class has their own strength and all of them are fun to play.
