Forum:Best single weapon

My current favorite class in multiplayer is a krogan Sentinel, which generally lends itself to charging in and just melee-ing the bejesus out of everything. When I'm in rage mode, I can take out a fully shielded Marauder/Centurion/Hunter with one hit on a Silver challenge.

It's a high-risk, high-reward, close-range setup, so it seems like a good thing to put with a shotgun only, thus keeping recharge time fast.

I'm curious what other people's favorite setups are. Stasis and a sniper rifle for free headshots? Assault rifle for the spray-and-pray approach? Heavy pistol and Infiltrate? Your thoughts, please.