Ooh - loads of fun, & can be as simple or complicated as you want it to be.
Just bake a bunch (approx. 2 person) of at least medium-sized Idaho potatoes & serve them with an array of toppings:
Plain & flavored butters
Chili (with &/or without beans)
Shredded cheese (different varieties)
Cheese sauce (again varieties if you wish)
Chopped crisp bacon (regular & turkey if desired)
Simple creamed shredded chicken or turkey or seafood (with or without vegetables as in "a la king")
Really - the list is only as endless as your imagination. It's an easy & fun way to feed a crowd. I mean - who doesn't love a good baked potato?