Have You Ever?
A great way to keep your partygoers engaged and stimulate conversation is to play Have You Ever? Make a list of silly questions; for example, have you ever gone to the store and realized you didn't have any money? Cheated on a test? Been arrested? If you need some inspiration, reasontoparty.com can help stimulate your mind and gives a list of questions you can use. Keep score if you want; the winner is the person or team with the most positively answered questions.
Blind auction
This party game will require you to buy a few items, but you can keep it inexpensive if you use the dollar store, or even homemade items. You can use wrapping paper or have a paper bag auction. Give your guests play money and let the auction begin. Bidding can become fierce. Don't tell what is in the package, but you can give vague hints. Items should be gag gifts like cheap plastic toys, skimpy underwear or "granny pants," candy bars, or a bubble-bath bottle filled with beans and labeled "natural bubble bath with a Jacuzzi experience." Consider adding a couple of nicer surprises like gourmet chocolate or a bottle of wine. The fun is when your guests bid and then compare the prizes they received.
Berries and cream
Ask your guests if they like strawberries or cherries; when you ask if they want to play a game, you'll probably get many volunteers. It will seem like a simple game when the guests see a single strawberry in their bowl and you tell them they will have to be the first to eat the berry without their hands. The fun part begins when just before the game starts you go around to each bowl and fill it with whipped cream. First person to find and eat her berry wins.
Board games
Adult board games are good if you don't want to add any extra fuss to your already long list of party responsibilities. Taboo is a game that is never boring; it is like a modern-day version of Passwords.
Split into teams. The object of the game is to get your teammates to guess a word on a card like "cat." Clues are given, but the card will list certain words that you can't use, such as "furry" or "meow." It's very entertaining to hear what people come up with. The Mensa Foundation rated Taboo as one of the best party games and awarded it the Mensa Select seal.