I watched Iron Man 3 yesterday and got inspired to start a new ID/Mech. Here's what I've come up with after 20hrs of playing time.
This LEVEL 13 Mech can be put together after about 3hours of playing time and you can then "rip a new one" in almost any player you come up against. I ALMOST defeated the #1 ranked player with this mech. He had just 1hp left when he defeated me.
The sword and the gun can be replaced with the Electric Rifle(level 10) and Skull Crusher (Level 11) and you can have a Level 12 Mech instead. A bit less gold reward but a much easier opponents.

My image server is a bit quirky so if there's no image, here are the specs.
SPECS:
Torso and Legs:Threetop: Level 12
Paws: Level 12
Specials:Firebee:Level10
Energy Shield :Level 10
Teleport1:Level 5
Charge2: Level 12
Harpoon Mark1: Level 6
Weapons:Swiss Cheese: Level 11
Fixed Point Gun:Level 13
Mach Cannon: Level 11
Heavy Gauss Rifle: Level 12
Durendal: Level 13
Modules:2x Armor Plating 5: Level 11
Multi Resistance Module II: Level 11
Kits:Cooling Kit 3:Level 10
Repair Kit 4: Level 11
Rockets Kit 3: Level 12
Physical Resistance Kit: Level 12