A couple of the other MFZ bloggers have discussed Micah Bauer's Component 6 System but I think it deserves another visit. Especially since we will probably have an influx of new players after the rulebook becomes widely available in print.
The core concept behind the C6 System is that it uses six commonly available parts that are easy to acquire in bulk. These parts are also common enough that they can be found in older sets and collections. This design philosophy also neatly sidesteps the question of, "Do I use Travis Bricks, Pneuma-Ts, and/or Taps?" Which makes every C6 design an entrant in the MittenNinja's 3T Challenge.
He's built a lot more things using the C6 design philosophy since the first flurry he posted to Flickr. He now has a station and vehicles/scenery to go along with the initial frames.
I built a mech using the C6 System.
I think it came out very swoopy. I'm calling it the High Speed Strike Ship, or HSSS 301 for short. It uses the following parts:
1 x 3040 Slope 45 2x1
3 x 3062b Brick, Round 1x1 Open Stud
6 x 4070 Brick, Modified 1x1 w/Headlight
8 x 3794 Plate, Modified 1x2 w/1 stud (Jumper)
13 x 3023 Plate 1x2
for a total of 31 pieces.
Right now I'm running with 2Rd/1G/2W for stats.