To encourage involvment I will go first. And I will try to be exhaustive.
Head: CHD-09-OXI (light weight, good radar and mapping)
Core: MCM-MX/002 (good EO, good weight, good lookin')
Arms: CAM-11-SOL (basic medium arms)
Legs: CLF-D2-ROG (best quads, good weight and move, look nice)
Boost: MBT-OX/E9 (good performance for the drain)
FCS: PLS-SRA02 (horizontal for ease of strafing)
Gen: KGP-ZSV (good performance for the weight)
Rad: RMR-ICICLE (works for me)
Ext: CSS-IA-64S (switch this for a light anti-missle if situation calls for it)
BackR: MM-AD/20
BackL: CWC-CNG-300 (I owe the game to this beauty...couldn't live w/o)
ArmR: CWG-B2-25 (there is a better light bazooka, but this one looks best)
ArmL: KWG-FTL450 (great range and damage, I FAR prefer this to a blade)
This AC is my basic "do-it-all" design. As I posted earlier I used this to beat the majority of the missions in Silent Line and some early arena opponents (I use a totally different AC for most of the arena). Some of the parts I listed aren't available initially but most of them are, and the ones that aren't were not too hard to get.
WHY...:
...NO BLADE? First off I don't like the forward rush that accompanies blade use. Secondly I find the damage and heat inflicted by the flamer is quite respectable. Thridly, I am garbage with a blade.
...QUADS? Good stability, the ability to fire back weapons while on the move, and they look the best.
...NO ENERGY WEAPON? Quad legs use a lot of energy. So does boosting. So does my EO part. I don't have the extra weight capacity to equip a generator that could give me enough power for all these essential tasks plus an energy rifle.
...NO MISSLES? In most missions I find that missles miss more often than not. Either the enemy is too agile, or the missles hit the ceiling/wall/pillar. Plus they are too slow against weak enemies. An MT might get an extra shot or two off while the missle is in the air (not a problem with the Chain Gun or Bazooka).
...NO INSIDES? I find the added weapon to cycle through during heavy combat more of a hindrence than any advantage a floating mine or some such device will give me. However on some missions and against some enemies a missle decoy might find its way into my AC.
How I use it:
I don't do a lot of jumping or boosting. Slow and methodical is how I use this AC. The back Chain Gun is invaluable, and I don't know of a better anti-aircraft weapon in the game. It's accurate and does a lot of damage (and heat). In really long/enemy intensive missions I will use the bazooka initially, to save the CGs ammo. The flamethrower is for destroying non-enemies (boxes, doorlocks, etc), and for quickly dispatching MTs that sit in doorways waiting for you to open them.
Use the EOs. I usually deploy them before entering rooms with either multiple enemies or one really nasty enemy (depending on my energy situation). After a few seconds/shots I usually turn them off to insure I have enrgy to boost. On at least one mission I remember the fact that they hover above you proved of great help. Think of a periscope that can kill.
Against a particularly hard target (i.e. enemy AC or boss-type) I find that circle-strafing with the Chain Gun and the EO deployed (watching out not to boost too much. thereby limiting the use of my EOs) works wonders. Not much can put up with the Chain Guns and the EOs for long. To insure continous lock during these engagements, try to stay 200+ away from the target, and raise your view so the bottom of your sight lock is about level with the horizon (so as to minimize the chances of his jumping above your lock).
I think that covers it...
Let us know how it works for you.