The best red I have found for under $12 is Cline Zinfandel. Cline is the winery that also makes Red Truck which was mentioned in an earlier post.

The best cab in the price range is Haywood which is typically less than $7 a bottle. The 2000 cab tastes like a $25 bottle

The best Merlot in this range (in my opinion) is Seven Moons. Sort of hard to find but if you can find it, it is worth a try.