Are you going to have room for everyone to sit down and eat? Or is it going to be more of a stand around with your drink in one hand and your plate in another type of evening? The type of event should help dictate the type of food. For a sit down, we've already had some great suggestions, jambalaya, chili, a casserole.
If everyone will be standing, I'd reccomend just doing some very simple canapes. Smoked salmon on a cucumber is a classic. I've been on a kick with blini lately; made well they're just marvelous. And the thing I like very most about them is that they go with EVERYTHING. Additionally, they're more filling than your average finger food. Last time I made blini I garnished with melted leeks, and it was a huge hit. You could top with mushroom duxelle, but you could go a lot simpler as well. Something like tomato or garlic confit would be great, or maybe a little julienne of roasted red pepper. Topping with basil or sun dried tomato pesto would be an interesting thing to do as well. I've done gougeres before, which were popular, shrimp cocktail done up is always well-recieved. I've done deep-fried ravilois before, with a variety of sauces, which was very popular. If you're serving wine, it seems like folks always like a nice selection of cheeses, though I've never personally enjoyed cheese very much.
