Plasma Grenade (Halo 3)

From MLGWiki

The plasma grenade does more damage than the Frag Grenade, and will stick to any players or vehicles it makes contact with; killing players and damaging vehicles or destroying vehicles.

Unlike the Brute Spike Grenade, it can stick to people and vehicles, but not walls or ceilings. Also, the plasma grenade is the only grenade of the 4 that will not explode if in contact by an already detonated grenade or other explosive.