There can be only One.
If you had to choose, between all the Mechs in Battletech, which would you choose, and why.
Personally, the Thor, is my favorite Mech of all time. From a visual standpoint, he's just intimidating looking (ala mech3 intro for example) he has solid humanoid chassis, and huge cannon on his shoulder. He's more like a Heavy Arms Grunt-type Mech. Not Excessive, Overburdened, Flimsy or Weak.
I feel, from a tonnage standpoint, he fits all around as a good mix of power, speed, and survivability making him almost untouchable when properly configured and piloted.
Can anyone else choose only one?
It's a hard decision.