In the SW era, I'd consider a HER-1 a pretty decent melee contender on the low end of the weight scale, crashing its 30 ton mass into an opponent after a run of 14 hexes (for 42 damage), which is pretty awesome for its tonnage and BV, but still no match in raw damage for a few heavier chassis like the OSTs and the CGR. I fondly recall an incident involving a HER-1 with a straight path to an opponent standing next to a 2 level drop; both units fell after the impact, but one ended up hurting a LOT more than the other. Note that a 20 hex charge by a LCT-6M is distressingly likely to result in severe internal damage or total destruction of body parts for the charging unit, depending on what it hits, which would seem to rule it out as a "best" choice.
The "OST Couple", DGN, or QKD can do 5/8 at 60 tons, delivering a 48 point charge. The basic CGR-1A1 can put 80 tons of sheer mass behind its max run of 8; it packs Assault class melee damage (64 charge damage), Medium class speed (5/8) and armor (same as a HBK), and Light class weaponry (5xSL), serving in effect as a "Medium 'Mech" with a weight problem (or "Gravitationally Challenged" by today's "politically correct" standards). Compared to that, punching or kicking with a 100 tonner pales into relative insignificance.
After that era, TSM and XL Engines change the melee game completely.
