For reference my cube list is here.
From what I observed in the sealed deck flights and drafts that I ran the following decks were quite common:
- Ux Mill - There's a lot of blue milling in my cube and a few artifacts to support it so all a player needs is to draft another colour to defend while the mill cards do their deed. I thought green would be the best pair for the additional defenders but it seems black (for creature removal) and white (for more control) were most effective.
- Mono-Red - One player twice managed to draft a bunch of burn and cheap fast creatures for a powerful sligh deck. The addition of Brimstone Mage gave the red player something to do with spare mana as did Burst Lightning.
- GW Mid-range/Tokens - I think this deck could go either way depending on what cards are present. My cube is 450 cards so in an 8-man draft up to 90 cards will get rotated out every draft. Lots of good tricks from white, mana ramp from green and tokens from both colours make this combination a force to be reckoned with if there isn't too much removal from the other side.
- Bx or Gx Infect - Saw this paired up a few times oddly enough with the blue milling cards. Not sure how effective it is as the infect creatures in my cube just aren't that big or imposing. I might try to add a Phyrexian Vatmother, Phyrexian Swarmlord and/or Phyrexian Hydra to give the infect players a little more oomph. Phyrexian Crusader doesn't always show up but when he does, it's pretty easy to get the win.
- UW Skies - Lots of flyers and tricks make this a very powerful archetype in my cube. There are a lot of flyers from both colours and if you curve out (especially with Mist Raven) the opponent will have a hard time keeping up unless they have a lot of removal. I won the last draft of the holidays with a UWb skies deck splashing black for Unburial Rites, Knight of Infamy and Go for the Throat. Coupled with a few card draw spells and some big flyers (managed to snag Isperia in the middle of pack 1) it made for quite a deadly deck.
- UWR Metalcraft - This one was only drafted by my brother who last played MTG in Ice Age I think when we were both in grade 8. He just saw big gold creatures, artifacts and a bunch of Metalcraft. Early plays were things like Sickleslicer, Lightning Greaves, Chrome Steed and then were followed up by big things like Jor Kadeen, Niv Mizzet, and Ulamog's Crusher. Even Spire Serpent was quite deadly in this deck. My favourite play of that draft was watching my brother play Ulamog's Crusher then equip it with Lightning Greaves and attack with Spire Serpent, Jor Kadeen and the Crusher while having metalcraft up.