Aye, the Shadowcat Omnimech has always been my favorite chassis. The default loadout in mech 3 was weird... 1 Gauss Rifle and 2 Er Med Lasers if memory serves me well... but once you rip out the components to customize it yourself, she's a beauty. Unfortunately, that game is really buggy on Windows XP. I CTD constantly... at least every time I've tried to install it. Also... it's terribly unbalanced in favor of pulse lasers.
Mechwarrior 4 works well, but I got bored of it eventually... and I got annoyed of MP because I kept getting shot with ER LRG LASERS just before firing my weapons, ergo getting my aim thrown off by the mech buckling over like 45 degrees. Mechcommander Gold is fantastic... and Mechcommander 2 just never captured my attention.
In terms of literature, I read four books out of Battletech:Twilight of the Clans starting with Sword and Fire (V). Man that was a good series... and it was good to learn the context of Mechwarrior 3.