NTG-D "Tens of Damage" (3xcLRM10, 1xcUAC10, 5xcSPL, cAP, TC1)

Max DPS>20 on a heavy!!

5x cSPL = 30
3x LRM10 = 30
1x UAC10 = 10(x2)

Efficiency UAC+LRMs: 67%
Efficiency UAC+SPL: 42%

If you want to break the rule, change the top cSPL to a TAG for better efficiency and quicker LRM targeting. This is a mixed build that generally just wants to rain down LRM/UAC fire. SPL are for when things get too close/ammo runs out/you just want to stab something. cLRMs have the benefit of dealing damage even under 180m in a pinch (though marginally when <100m) thus can be used more freely than usual.
Basically you're bringing a pseudo-LRM boat in case you get Polar Highlands. For the rest it's got a solid punch and LRMs have a suppressing effect in brawls as well.