Owling Mine is a fun deck. Not to play against, though
You probably know, right? When it gets off, you're just locked there, and then you take the damage, take the damage, take the damage...
It's so great however, that it's mostly built out of pretty bad commons and uncommons
Another very interesting deck is the Masterpiece that Anton Goldblatt finished second with in the regionals in Connecticut and Mike Flores looked at last thursday in mtg.com. I mean, it might seem even totally random, but it just has a bit against everything. It was very cleverly built with the metagame in mind. As Flores said, not many would play a Birds of Paradise just to play a Wrath of God, but this deck does it. And it's also qutie versatile and diverse that I'm thinking about making a version of it. I've been thinking about stuff like this, and this really encouraged me. However, Flores was probably also correct that it won't see masses of play, but should be a small staple at tournaments.