On the weekend I finished basing and painting a good chunk of the Space Marine forces I want to finish for Epic 40k. While both will have good times killing Orks, Squats, Tau and Eldar, I really want to play some more "classic" games set in the Horus Heresy - the 40k "period" that really got Epic launched.
For the "loyalists", I went with Dark Angels, a chatper that is classic, unique and reconigizable without being uptight (Ultramarines), absurd (Spacewolves) or dumb (Blood Angels). I have to say, the Imperial Fists would have been cool too - but the Dark Angels win because they paint up way faster!
It's a small forces - just one tactical detachment, with some Dreads and Whirlwinds in support.
I have finished a lot more of the "traitors" - the Emperor's Children (or inspired by the Emperor's Childern). I used the actual Space Marine models to capture the rebel feel - these are the forces that rebelled, not the tools who hang around the Eye Of Terror sticking a tail and five horns on to every piece of equipment they have.
Each side has some flyer support, so the Marines can fight in true "marine style" (i.e. come in from off-planet and kick butt). There is still more to finish for each side, but the great thing about Epic is that it paints stupidly fast, so I hope to have the forces pretty much done in a couple of weeks.