Towards the end of last year, a friend of mine finished building his own Zone Mortalis board, since then we've been playing small multiplayer games using the Great Crusade lists from Forge World's Horus Heresy book series.
These games have proven to be very entertaining indeed, and have spawned a narrative-driven Horus Heresy campaign. Personally, I've been interested in getting in to 30k-era gaming for a long time, but I've always been put off by the cost. For this campaign each player would be building a 500 point army that would won't grow massively over the course of the campaign, so it's the perfect opportunity to build a force using some tasty Forge World kits without breaking the bank.