9 cup Popcorn, air popped
1 butter flavored cooking spray
1 tsp chili powder
1/2 tsp salt
1/2 tsp garlic powder
1/8 tsp ground red chili pepper (optional)

Directions
1 Preheat oven to 350 degrees F.
2 Line with foil a 15X 10-inch jelly roll pan.
3 Layer the popcorn on the jelly roll pan and lightly coat with cooking spray.
4 In a small bowl mix together chili powder, salt, garlic powder and red pepper (optional). Pour over popcorn and mix together.
5 Bake for about 5 minutes (make sure popcorn is hot). After the first 3 minutes gently start to stir the popcorn.
6 Let popcorn cool and serve.

Little late
I never do it by measurements I do it by eye and taste so I tried
White popping corn.
Couple of tablespoons of lemon zest
Teaspoon or so of dill (fresh is always better)
Throw together when really hot and mix
Oil is the way to go when cooking
If you use microwaveable butter the more the better throw everything in when hot and shake away let is sit while hot for flavors to combine.

One other is just cayenne pepper or chipoltle always a winner in my book.

PooMaster
http://www.pooplatter.com

This is a little late to be of use for the party but every once in a while I'll stir up some fresh sage in melted butter and pour over popcorn. We have it growing out back so it's easily accessible. I don't know that it's worth buying fresh sage just for that.
Maybe you could make this sage pesto recipe and use the extra for the popcorn:

1/2 cup packed sage leaves
1/2 cup packed parsley
1 cup freshly grated parmesan cheese (key to any pesto, don't by pre-grated)
2/3 cup walnut pieces
3 gloves crushed garlic
1/2 cup olive oil
Put everything but olive oil in food processor and run until gritty.
Gradually add olive oil.

Experiment with the ingredients for your taste. I think I use more sage and less parm.
Serve with pasta or butterfly pork chops and put the sage in the chop then grill.

Adamsdad

"If not you, Who? If not now, When?"