Ok...here we go...

White:

Sauv Blanc: Anything from Malrlborough, NZ is typically good. Specifically I like Oyster Bay (10-12) and Rain (15-18).

Chardonnay: I only like the super oaky/buttery ones so beware but Kendall Jackson ($10-14) and Sonoma Cutrer (15-20) are my usuals.

Red:

Malbec: Easily my favorite drinking wine. Trapiche ($15), Norton ($12), and Layer Cake ($15) are all good.

Cab: Louis Martini is arguably one of my favorite wines regardless of price and you can find it for $12-$18 depending on the place. There's a few variations (more expensive versions) but the Sonoma valley one is the one I'm referring to. The cab Jack mentioned is also good and generally anything from Argentina or Chile (Montes Alpha comes to mind) in the 10-20 range will be drinkable and have a little more spice/complexity than its Californian friends. California cabs will be a little more smoother but I don't enjoy them, a few exceptions, as much as South America. The Francis Ford Coppola vinyard (claret, Cab, a few other blends) are usually around $15 and good.

If you like cabs, try Haut-Medoc's from France. Basically a cab base but with other grapes blended in. Very good with steak or anything else rich. I like them as a drinking wine but most people find it too full bodied alone. You can find some of the cheaper (Chateau Greysac is the one I usually get) for like $16.

All above pricing is based on my NYC experience. I've found in Texas thigns are much more affordable. For example, Kendall Jackson was $16 in NYC but $9 at Walmart here in Texas.