Is it opened or unopened? If it's opened for weeks it may not be good anymore. If it's unopened I usually save them in my cellar for when I do need it.
Although I mainly prefer to cook with vermouth now whenever a recipe calls for white wines, you could make risottos, white clam sauce, poached fish, various marinades, there's no end to the possibilities.
You could help by being more specific about what kind of wine it is, unless you're trying to keep it a secret of course. But your question is kind of like "I have a piece of meat, how should I cook it?" It really all depends on what it is iykwim.
I use white wine in my onion soups, once braised a leg of lamb in about 3 bottles of it along with half a dozen heads of garlic, recently used some in a simple lemon garlic shrimp with fresh tomato pasta. Often use it for deglazing a skillet after roasting chicken in it. Like others have said, there are lots of possibilities, other than just drinking it.
Is it a wine you're used to cooking with? I have a favorite red, and a favorite white I cook with. I'll throw in the Marsala here and there and whip out the port when I find it appropriate, but I've learned my lesson more than once by throwing any white wine into any dish. I was making risotto once, I had already sweat my shallot and garlic, was giving the grains of rice that quick saute, and too little too late realized my only choice of wine was moscato....it was disgusting.
In a large rondeau combine butter, shallots and parsley, cook until shallots are translucent. Add in seafood stock and lots of salt. Then goes in 2 lbs of mussels and 2 lbs of clams, 2 lbs of 21-25 shrimp, empty the bottle of wine into the pot and cover with a lid immediately. Steam for 3 to 5 minutes until shells open and shrimp are cooked. Get a baguette, grab some beers, and call some friends over.