TheHand
Adventurer
The Solaris Tournament has a lot to it! You start as a rookie mechwarrior with 3 mill credits. Basically gets you a light mech. They have a wide variety to choose from (Though clan stuff is very expensive and hard to get). You earn fame and character points by landing hits on turrets, targets, other players mechs. As you collect credits, you can buy abilities and other mechs. It's a blast!
Oh, that's really creative! I like how it has an advancement system but doesn't lock out new players.
Recently I've only played small games with friends (diving into the rpg Mechwarrior: Destiny a bit now), but back in the late 90's I ran a casual tournament we called the "Junkyard." Everyone brought in 2 Mechs (Inner Sphere only), one had to be a Medium, the other Heavy. Then you paired off against 2 others.
The winner got to repair basic things like armor, internal structure, but if you lost any components you had to strip them off the salvage of your defeated foe. Alternatively, you could try to salvage one of their Mechs or replace equipment between them. When everybody got to the semi-finals and final rounds, everybody was fighting together with these frankenstein'd beasts held together by chewing gum and duct tape. Hence "The Junkyard." For the winner we bought a generic sports trophy, pulled off the sportsball player, and glued on broken Ral Partha miniatures (repainted gold).