Red is generally the best choice, since the acid and tannins in most red wines help to cut the proteins and fats in the steak. Similarly, red wines are the traditional pairing for cheeses (although I find that many high acid white wines do pair well with certain kinds of cheeses).
Having said that, it is possible for white wines of a certain type to pair well with steak. Specifically higher-end white Burgundies and wines that are styled similarly (California chardonnay specifically in mind). Why? First, the creamy richness of this type of wine leads to a mouthfeel and intensity of flavor that CAN stand up to grilled meats (especially steaks) and other richer and or fattier cuts of beef. The other factor going for this type of wine is that white Burgundies contain a good deal of acidity (even after the malolactic fermentation) and that helps to cut through the fat and cleanse the palate. The smokiness of oak (which isn't necessarily a feature of white Burgundy and California chardonnays, but is common) can lend harmony to the pairing. There are other wines, to my mind, that could do well instead of chardonnay (which is the grape in white Burgundy). Semillon and semillon based blends (mid-range to higher end white Bordeaux and several richer white blends from Washington state come to mind) especially if they are of a richer, creamier style. Northern Italy produces some very respectable white wines that are similarly styled and would fit well (find a *good* wine retailer and tell him what you want to do - you'll know that you've got a good wine retailer because they won't laugh at the suggestion). There are also some great South African and Australian chardonnays that would do well (Australia also does some very nice things with Semillon).
Preparation plays some role as well. Especially if you are serving a cream sauce with the meat. Compound butters flavored with shallots/garlic and green herbs would also make a nice liaison. Especially with semillon based Bordeaux. Finally, if you are serving a tartare, then a white wine might be a great choice (or dry rose).
Of course these are only guidelines, but I hope that I have given you an idea of the reasoning behind it. Taste everything, compare flavors and test your theories before you put them in front of a group of people. Who knows? You might discover the next great new taste sensation.
Which is classier? To me, knowledge and good flavors are always classy. Those who cannot open their minds to new ideas are not. It shouldn't be predicated on what color of wine you choose.