H.W.
I like to serve things like:
cut-up fruit,
cut-up veggies,
hummus (it's easy & cheap to make your own) & baba ganoush (eggplant dip--als super-easy & inexpensive)
whole wheat pita bread,
popcorn (air-popped is great), with brewer's yeast is good too...
bruschetta with whole-grain bread, tomatoes, garlic & basil,
salad bar w/lots of different toppings like garbanzos & kidney beans, pickled (or non-) beets, sunflower seeds, soy nuts, or other nuts (tamari almonds are yummy), crumbles of feta or cubes of farmer's cheese, olives, etc.
for main dishes, I like marinaded skewers of meat & veggies (you can make ahead of time; husband hunts, so we like to serve wild duck),
veggie chili (or with ground turkey),
instead of hotdogs we like chicken-apple sausages, the thin links that say they are for "breakfast",
for desserts, frozen melon balls,
frozen fruit skewers,
homemade sorbet (watermelon, or whatever's in season)
Hope this gives you some ideas! I'd love to see more from others...