Lately I've been thinking about a raid just using Blizzard's built-in loot system. Set a threshold of Epic and just go:
1. Want the item for your main set - roll Need.
2. Want the item for your off-set or sidegrade - roll Greed.
3. Don't want the item - Pass.
4. If everyone passes, an enchanter scoops it up and disenchants the epic.
I know this system would probably end in drama and tears, but it would be so fast and easy. You could spend more time actually doing stuff, and less time handing out loot. Yeah, someone might win two items over someone else, but it will average out over time.
The biggest issue would be people who raided for different amounts of time. A guild would have to deal with attendance issues apart from the loot system. But that might be a good idea anyways, rather than relying on your loot system to motivate people to show up.