#1 MAD-IIC-D
2x LB10X, 2x ASRM6, ERPPC, ECM
Still a favourite of mine and consistent performer. I may not look that great, but I am more consistent in this than any other Assault 'mech with any other build. Sure, it's not my most damaging build, or highest DPs, or biggest Alpha, but it does *serious* work.
#2 HBK-IIC-A
6x MPL
This simple beauty has quickly become my most played 'mech and for good reason. What it lacks in range, it makes up for with mobility, firepower, sustainability and staying power. While the 48 damage Alpha was nerfed to 45 recently, it now runs noticeably cooler as a result, for greater sustainability. Corner pokes and hill humps like a champ.
#3 RVN-4X
2x LPL
My 4th most played IS Light (just behind the RVN Hero and 3L, way behind the 2X), this is the only one of those that has never needed a build change. Even with the reduction in LPL damage from 11 to 10, that 20 damage is nothing to sneeze at from a 'mech than can get (almost) anywhere, sharpish.
#4
LB10X, SRM4, ERPPC
Sure, it's not packing much firepower for a Heavy. Sure, those arms are getting blown off. Sure, 2/3 of the weapons are low mounted. Sure, I haven't got room for enough ammo. I'll *still* blow off your arms and legs, then kick in your gorram cockpit!