Chateaubriand, also known as beef tenderloin, is by far my favorite choice for Christmas dinner and the only wines that I consider bold enough to stand up to rare or medium rare beef are Cabernet, Merlot or a Bordeaux Blend.
Here is a list of some wines between $20-$30 that I think are a perfect match for Chateaubriand.

Philippe-Lorraine Napa Reserve Cabernet 2002
For the last few years Phil has been able to share this family oriented pursuit with his son, Phillip, Jr., also an accomplished winemaker. Together they use old world techniques and a hands-off approach in order to produce a rich yet elegant Cabernet in a more European mode. All of the grapes are sourced from vineyards in the heart of Napa Valley, but this father & son team strives to steer away from the over-the-top ripe style that is in vogue today. Together with their growers, the Baxters work towards an expression of the soil rather than the winemaker. Food friendly and elegant, this wine is designed to enhance a dining experience. Oh yes, it is also a tremendous value with very modest pricing for Napa Cab!

04 Stratton Lummis Cabernet Sauvignon, Napa Valley
From the heart of Napa Valley comes a Cabernet Sauvignon that tastes and smells like currants and rich chocolates. Stratton Lummis is dedicated to Cabernet Sauvignon from the top vineyard estates in Oakville and Rutherford.
It took thirty years of friendship before we were allowed access to those vineyards. It also required that we sign a document guaranteeing that we will never reveal our vineyard source. However, if you stood in the vineyard and threw a rock you would hit S.........Oops! We better not. It is these unique estates that allow us to deliver wines with distinct personalities. The estates that take their wine from these vineyards charge hundreds of dollars for a bottle of their wines. We named this wine after our Great-grandfathers. We bring it to you at a price that our Great-grandfathers would appreciate.

Provenance Napa Cabernet 2005
For Provenance winemaker Tom Rinaldi, achieving this cabernet's characteristic "Rutherford Dust" is a matter of selecting the right fruit. The majority of the grapes for this wine come from outstanding Rutherford vineyards, including Beckstoffer George III on the east side of the appellation and the Provenance and Hewitt estate vineyards on the west. Aged in a combination of new and used American and French oak barrels, the wine displays classic mocha and toffee characters on the nose, with hints of clove, violet and chocolate in addition to lively red currant, black cherry and wild blackberry aromas. On the palate, the wine is richly textured, with flavors of dark chocolate, blackberry and espresso on the entry, with black pepper, black tea and green olive mid-palate. Balanced, with plush tannins and a long, elegant finish with the signature, cocoa powder notes of "Rutherford Dust."

Edge Cabernet Napa 2005
"It’s tough to find any Napa Cabernet for $25 these days, much less one this stylish. Ray Signorello, Jr. made this full-bodied, lightly oaked wine from grapes purchased all over Napa Valley, including Stags Leap.

Newton Claret Napa 2004
A sophisticated blend in the Bordeaux tradition with an unexpected addition of a small percentage of Syrah, this wine is all about balance and finesse. Pretty aromas of blueberry, black currant, and red cherry lead to a layered, medium-bodied palate of blackberries, cherries, and plum with a touch of brown spice. Supple tannins, a light touch of oak, and pleasant acidity harmoniously support the clean, bright fruit.