Large Group Games
The best games for a party are those which can involve a large group of players, because that way everyone can be involved. Games like this include "Apples to Apples," a game with a huge number of cards, or some variants of "Pictionary" and "Guesstures."
Board Game Party
Someone with a large board game collection will have a few interesting board games mixed in with a lot of the classics and staples. Invite everyone over for a game night, and have them bring some of their favorites, then split the party into groups of people playing different games. This is the type of party that works well with slightly smaller groups. Some games for a night like this include "Trivial Pursuit," "Monopoly," "Cranium" and "Clue," just to name a few.
Tournament Gaming
Get the competitive streaks in your guests going by setting a prize and a tournament bracket up during game night. Set up multiple games, or just a scoreboard, and have the player or groups of players who are doing well move up the rankings. At the end of the night, the player who has won the most games wins the prize. This is the type of party which works well with short games.
Drinking Games
Staples of the adult party, a drinking game should only involve a group of adults able to legally enjoy alcohol. You can play a number of games with drinks, and sometimes with other objects like cards or dice. What makes these games interesting is that the penalty for losing is that the corresponding player must take a sip or a shot. Games include "Kings," "High or Low," "Never Have I Ever," and a handful of movie-themed drinking games. Always have a non-drinking designated driver on hand for those who can't stay overnight.