My favorite class in ME2 is the Vanguard by far.
My favorite class in ME2 is the Vanguard by far. Not only is he lethal at close range with the shotgun but he also has range with the SMG. My strategy is to pick off enemies 1 by 1 with the SMG until there are about 3 left. Then I switch to the shotgun and use charge to take out the stronger enemies. If enemies get to close for comfort, I will use the occasional pull to keep from getting surrounded.
Overall Charge is a great way to take out a strong enemy. Just don't use it to early because if you get surrounded after using it, it could mean your death.