I really like Vina Santa Rita Reserva from Chile's Maipo Valley, especially the merlot, but also the cab. About US$12 at Total Wine. Spend the extra couple bucks for the reserva & pass on the regular bottling.

The Concha y Toro "Diablo" line from Chile's Rapel Valley is about $8 everywhere. Try the Carmenere along with the cab & merlot.

From southwest France, Chateau d'Oupia, from the Minervois region. I got a bottle as a gift and liked it so much I bought a case at A Southern Season (a local huge food & wine specialty shop) for 8.50/btl with their 15% case discount.

Especially when you're shopping for bargains, consider the case discount once you find something you like. Some shops even give the discount for a mixed case of 12.