Slam or Dominate. Slam is a good biotic power, but it isn't any better than push or pull in my opinion. Dominate (the Justicar's daughter's fourth power) is an organic form of AI Hacking and is great. Take a Krogan's shield down then use dominate and the battle will turn quite quickly.
I like inferno grenade, its like a stronger version of incinerate, though it can be hard to hit with sometimes. Warp Ammo can be useful depending on your class.