Thank you, University of Adelaide. It turns out that a researcher there, Professor Kym Anderson, has been engaged in a lengthy project analyzing the world's grape-growing regions and has determined—among many, many other things—that Cabernet Sauvignon is the most widely planted wine grape in the world.
Of course, there are variations by region—in Kazakhstan, for instance, Rkatsiteli is the most widely planted variety. In Thailand, somewhat mysteriously, it's Syrah. But overall, Cabernet wins. Be glad. Twenty years ago the world's most planted grape variety was a Spanish white grape called Airén, notable primarily for being incredibly bland.
And so, seeing as how there's so much darn Cabernet in the world, a little advice about which ones to buy seems in order. Here are a few top bargains. (And, if you truly want to indulge your inner wine geek, Anderson's wine-grape study is available for free as a PDF e-book.)
2013 Mulderbosch Rosé of Cabernet Sauvignon ($10) Rosé in winter? Cabernet rosé? From South Africa? Why not? Cabernet makes for a rosé with some oomph, ideal for cold weather, and Mulderbosch's strawberry-floral bottling is a fantastic deal.
2012 Trivento Cabernet Sauvignon Reserve ($11) Argentina's Mendoza region is better known for Malbec, but it also produces impressive Cabernet, as this darkly spicy wine shows.
2011 Columbia Crest H3 Horse Heaven Hills Cabernet ($15) If you like your Cabernets bold and luscious, this Washington State wine is an ideal choice.
2012 Foxglove Cabernet Sauvignon ($15) Bob and Jim Varner, who are known for their extremely good (and fairly pricey) Pinot Noirs and Chardonnays, also make an affordable line of wines under the Foxglove label. Their Cabernet is a perennial steal.
2010 Heartland Cabernet Sauvignon ($16) Star Australian winemaker Ben Glaetzer makes this black currant–rich Cabernet with fruit from the warm Langhorne Creek, southeast of Adelaide. (Note: The 2012, which should be in the US soon, is also terrific).