Addict said it all !
It depends on what kind of party are you planning. Who are the visitors?
PIZZA ! Everybody likes Pizza !
Pizza for sure! Chips, pretzels, maybe a vegetable tray, cheese tray, soda, iced tea....just really depends on the type of party and the age of the partiers!
Junk food...
It depends on the party you are planning to organize and also on the people who will be there. Keep in mind that there might be different tastes or needs (like some people might be vegetarian or allergic to gluten). So if you manage to include a bit of everything you can satisfy every taste!
Pizza is a good compromise because generally it keeps everybody happy and you could order different kinds.
Alternatively, you can make a round of appetizers.
Thisphotogallery is pretty good to get an idea. It all depends on your budget and the time you want to spend on it though! Enjoy. (: