Jenner! Lol! There was a mission on Mech 2 for the PS1 that was so hard, annoying, yet epic. The player was forced to use only a Jenner to beat the entire mission. The foes were in medium to heavy mechs. I felt such a rush of amazed excitement when I finally beat it. Crappy weapons, armor, and so forth to triumph with!
Oh yeah and the Mech 2 clan trials to achieve the final and highest rank with the Firefly. Had to beat an assault mech with nothing but light lasers, short range missiles, and no armor to speak of with a small arena to fight in. That was a terrifying fight.
Warhawk! Mech 2 for PC. Amazing assault mech with 4 PPC cannons. It was pure brutality. Anything other than an assault mech was killed instantly or turned bright shiny red in one hit of quad-linked PPC's.
Annihilator and its trade mark LBX cannons. Shotgun madness.