Every time we start a new campaign we design our own four mechs - light, medium, heavy and assault - to form our lances. The only rules this time around were the mech has to be based on an existing chassis and we're allowed to use basic tech only (no ER lasers, XL engines, FF, ES, advanced electronics or UACs) since it's a late Succession Wars campaign.
I have a custom Atlas variant called the Atlas PWNED-LOL.
It's got four Medium Lasers and two AC20s in the torsos, with an LRM10 in the left arm. I designed it using what I learned from fighting his customized Banshee (all stock but AC5 was upgraded to an AC20) to make a fearsome close combat machine.
The point of the design is that, since its Autocannons and Med Lasers are in the torsos, you can fire all of those weapons at point blank range and your arms are still free to punch. Which means if this mech can stay in melee range for even one turn it will deal enough alpha damage to blast anything under 90 tons all the way back to the stone age.

I also have a Trial Jenner, my favorite MWO Centurion build (1 AC10 2 MPL 1 SRM6), and a Quickdraw with all the lasers moved to the arms and two SRM6s in the left torso in my roster.
-Cracks knuckles- Now if you'll excuse me, I have some territories to capture on our made-up island continent.
