I
LOVE that game!! My favorite mechs in order of weight are the Daishi, the Mauler, the Madcat,the Argus, the Hellhound and the Puma.
My usual load out is an AC20 of some kind. 2 clan ultra AC 20's on the mauler and daishi and 2 LBX AC 10's on the Madcat
Followed by a clan LRM of some type. It just depends on which mech I am useing. Finaly clan ER med lasers are a must on all of my mechs. THey are light enough to pack a lot of them and still have room for other things. Group fireing 6 of them will quickly annihilate your enemy.
If I know ahead of time that I will have to be makeing distance shots or takeing out turrents I will usualy try to pack a light gauss rifle or an ER ppc because the next longest range weapons will put you withing range of most turrents when you use them. Also fireing from max range with a light gauss is usualy far enough away to keep the A.I. from realizeing that you are shooting it to hell.