Like so many folks, I'm kicking around the whole Imperial Guard thing.
Though, I'm more into making it a modeling project. Now, one of the issues with Guard is that there are a LOT of Guardsmen. I'm looking at running predominantly mech, so I'm looking at 50-60 guardsmen. (at least 3 chimera-mounted vet squads, and a platoon or two).
One of the major modelling issues, then, would be how to diferentiate the guard? I'm thinking more in terms of head-swaps. Thankfully, Pig Iron (by way of the Warstore) sells like 20 heads for about $5. So, modding the squads won't put me back that much.
So, here are some of the ideas...
The Replica Army
From F.E.A.R, this theme lets me get some mech in there. Head-swaps galore. I'm thinking of the guy in the lower middle. It's a bunch of drones with guns, semi-workable ballistic skill, and so on and so forth.
I've also got options for Sentinels and heavy weapon folks. The Replica Heavy can serve as a one-man, two-wound heavy weapon guy, and the REV battle armor (if I could ever find a way to do it) would be a good Sentinel.
In keeping with game fluff, I'd be leading it with a Primaris Psyker, because Paxton Fettel rolls like that. Plus, I'd probably roll with Combat Psykers just to simulate the effects of all the lovely phantasmagoria the game's a trademark of.
The infamous space-nazis of the Killzone series are a good Guard stand-in. I'd need gas masks, but the real modding issue would be the vehicles. Most Helghast stuff is hover-tech; we see big hovertanks and hover APCs. I'd be doing a lot of modding, but the foot soldiers have lots of versatility.
Examples of the infantry:
If we're talking about hordes of drones and nutters, the Combine out of Half-Life 2 is a solid contender. Hordes of re-programmed trans-humans with crappy aim, light arms, and armor support.
The real cons come with doing any vehicles. ALL of the vehicles outside of the APC and the Hunter helo are pretty damn alien. There's not a good analog to the Russ; the Strider is a fourty-foot-tall tripod with a chin-mounted gatling gun and a disintegration ray. The real question would be finding the correct GW components to do it.
It would look damn cool if I could pull it off.
The Hunter: (little Striders...almost sentinel-sized)
NOTE: I'll come back and try to slap the pics in.