i think titans have the best grenades for PvP. The lighting grenades are probably the best, and most annoying. The bubble is mainly just support, so i would use striker, if i ever ran titan in pvp. The fist of panic is called that because it is primarily used on one player. the smash can wreck bubbles, and is probably the best for control, where there is a great chance of groups on the zones. Also, i cannot escape the fist of panic. I jump as high as i can away, and still got killed by it. One last thing: shoulder charge. It's a one-hit melee after you sprint for a little bit. Sprinting into a wall and then going around a corner into someone is a good way to use it. My friend went positive (i forget the ecact stats) with just shoulder charge. Other than that, my advice is to play on the character you are most comfortable with. I am most comfortable with a hunter, my friend is with a titan, we both do good. Consider trying out the other classes, see if you like the feel better. Good luck!