Faction: Undetermined. I'm not as familiar with the faction alignments as I wish I were but I do know that I prefer the Clans to the Inner Sphere. After all, pseudo-religious, militaristic fervours is such a fun foil to socio-political posturing and conflict

BattleMech: Mad Dog/Vulture. It is an incredible mid range 'mech with capacity for any situation: speed enough to work in a surgical strike (not perfectly but with some refitting it could work just fine as a chassis), weight enough for heavy artillery, armour enough to hold its own in a plain firefight, heat efficency enough for a long term engagement. Mad Dogs are an easy choice to augment any lance or star, versatile enough for a veteran pilot and median enough for a whelp right out of his sibko

Weapon: PPC. It is the epitome of heavy duty energy weapons. Deals a ton of damage, increases the heat of your enemy (if I'm not remembering something completely different), energy so it doesn't risk exploding after the wrong shot or too long in the heat and doesn't run out when you most need it and a great sniper weapon despite it's relative projection speed

Faction: Clan Coyote. You might could say it came to me in a dream. :P
Always liked coyotes, happen to love science, and reading all the fluff on them they just seem like the best faction out there to me.

Battlemech: Pariah. Lots of good base configurations, but I happen to like my custom version with an LB10X, Large Laser, 2 medium lasers, and 5 small lasers all tied to a targeting computer with 5 jumpjets to help with movement. This thing has amazing heat management and can really pound things to scrap.

Weapon: Probably either the LB10X or the Large Laser, clan or inner sphere. Just happen to like those weapons. They link well together, they do good damage, have good range, and the LB is a good multiishpurpose weapon.

Faction: Clan Wolf-in-Exile. I am a warder through and through. Even though they supported that stravag Steiner in the FedCom civil war, they still are my preferred faction. Clan, but not as hardcore.

Battlemech: Really depends on for what. But I do like assault mechs. So would have to go with the DireWolf. Just Old fashioned, and since it is Omni, you can keep it updated as far as weaponry. And I prefer the more serious, less anime look of the 3050 era mechs.
Some of the later just looked ridiculous

Weapon: Hrmmm.... Again depends if i want Short range or Long Range.

For short: AC20, either an UAC/20 or LBX20. Especially in a twin configuration.
For Long: ER-PPC, Clan. Premier energy weapon. Just nasty when it hits. Enough to kill a mech in one shot if you get a headshot off.

Wolf-in-Exile supports the Davions, since their current Khan is the son of Morgan Kell. The reborn(if you want to call them that) Wolves under Ward technically support Steiner, what with Katharine being Ward's Bondsman.

Guess i got that flipped somewhere. I was under the impression, since hte ARDC is on the edge of Stiener space towards the clans they allied with the Steiners now. time to refresh the memory

Currently having only played Mechwarrior 3 my choices may be subject to change but for now,

Faction: Likely Clan Wolf or Coyote. Don't know much about them or any Clans yet but I'm sure one will fit for being cool!

Mech: In MW3 without question the Blackhawk. It can do just about everything I want without the shortcomings of assaults and scouts. But if I had Uller in MW3 I'd likely love it! Speed is rather important to me, I like no less than medium speed.

Waepon: Tough one, I do have a liking for at least two or four Mguns on my mech lately. Also like AC10 and some small lasers for rapid energy fire at close range. Generally I like small and medium weapons with modest ammo amounts for I like to have multirole ability. I like to get in fast, Hit hard, And get out of that trouble faster than I got in to it.

Faction: Haven't decided yet. They all have their pros and cons. As long as it's not the robes ...

'Mech: my top 3
3. Hunchback
It's big, it's bad it's ugly - and it can kick your Mech butt pretty hard if you get too close. The way they designed the AC/20 chassis is simply unique.
2. Raven
The cutest shape you can imagine on a 'mech, yet it's a great design for electronic warfare and good teamplay. Send it out to NARC a target, then bombard the prey with your NARC equipped LRM racks. You will love the fireworks.
1. Marauder ftw!
The first time I saw the Unseen version of it, it hit me like a NAC/40 shell. Good speed, decent armor, and a weapon loadout that makes you run away if you are at the wrong side of the barrel.

Weapon: PPC, no matter what version (Standard, ER, Heavy, Light, Snub-nose, Support, Naval). I've always been a sniper, and the PPC - especially the ER version - can be VERY nasty for that job. No ammo dependency, the weapon's light, it's not THAT hard to pack enough freezers into the 'Mech to keep the heat to an acceptable level (even with just L1 tech), and most of all: the technology behind it is totally awesome.
Quite a few of my Mechs I designed (like the Battlecrow, you can find a pic of it here on FA) are PPC carriers, and it's one of the more important weapons on my Ravenlord Missile Cruiser (pic's here on FA as well).

Lets see.

Faction: faction wise im dancing between Clan Wolf and Clan Smoke Jaguar, Thier fighting styles and clan abilities are so unique that its really hard to choose just one >_>, but if i HAD to pick one...clan Wolf for Sure.

Mechs: ill follow up on Warmock's
3. Jenner/owens= These two and thier variants are closely tied in my heart, speedy, hard hitting, and jumpjet fittable, they are cruel little mechs in the right hands, and with a MASC equiped...well Cheetah fight anyone?
2. MadCat/TimberWolf= A Serious all Round Mech, the serious epitome of clan versatility, able to mount almost near any weapon in the mechwarriors armory it is simply a DAMN fine machine to add to any lance, Its newer brother, MadCat MKII is a little rougher in that it uses gauss cannons but..meh.
1. Daishi/Dire Wolf= even if its mostly favored by Clan Smoke Jaguar, its truely some Seriously Heavy Metal, 100 tons of pure destructive potential, while it may be slow, its still one of the MEANEST mechs in existence, do NOT get in its cross hairs.

Weapon: Clan Extended Range large lasers, i have yet to see a weapon that can be coupled so well with a salvo of missiles, Where PPCs, gauss, and Autocannons have thier bulk and Sheer damage blasting abilities, they HAVE to have at least three slots to fill in each, which most mechs dont have open all the time. Two slots, energy or Omni thats all ya need and its damage output is Simply outstanding for it, even its heat output is offset by a few heatsinks and some quick learning on how to fire them without overheating.

Faction: Clan Wolf in Exile, I guess. They're cool guys.
Mechs: God, don't make me pick just one. I guess I really like the Kit Fox/Uller variant A--it's a well-armored light mech carrying two medium lasers and a GAUSS RIFLE. Clan Jade Falcon is damn right for using so many. My favorite Inner Sphere mech is likely the Warhammer--effective, and it's an excellent design(IT LOOKS SO FUCKING AWESOME IN MECHWARRIOR: LIVING LEGENDS!).
Weapon: Probably the Clan Large Pulse Laser. It is a rapestick on anything that carries it. I mean, you go up against a rifleman iic with two of those things and you likely will die.

Faction - Davion, hands down. Federated Suns are an entertaining blend of inspirations and I'm a fan of the Capellan March (particularly since my favorite university is there. Word out to my Goshen alums!).

Mech - Marauder. It looks mean, and some of the configurations are truly badass. Defines the ideal of the IS 75 tonner in its upgraded forms.

Weapon - Gauss Rifle. Who doesn't love the idea of a 15 damage weapon with massive range and zero heat?

Clan Cloud Cobra. I'm an aerospace nut and scientist, it just fits.

Mech - Red Shift. Mnn. Turbocharged MASC. That is all.

Weapon - Machine Gun Array. I'm a bastard. That is all.

Clan Wolf in Exile. The freeborns need some protection.

Mech - Daishi. They look cool, have armour, and for omnimechs, weapons layout doesn't matter as much.

Weapon - Hyper Assault Gauss Rifle. I am the greater bastard! XD

Kurita- 14th Legion of Vega (pre Edo; hard to keep playing as them when the regiment was wiped out!), Amphigean Light Assualt/Genyosha (post Edo)

Hatchetman or Hunchback; especially my own, customised Solaris VII designs

Big Axe with triple strength myomer. For ranged it has to be a PPC