- Steam has a large collection of games. Getting an account is free, however, most of the games you'll want will cost money. It has sales pretty frequently though.
Some fun large group games include:Jackbox Party Pack 2 - $24.99 - Comes bundled with 5 games including Fibbage, a game about lying about some crazy trivia; Earwax, a game about silly sound effects; Bidiots, a game about the world's best or worst art auction; Quiplash XL, a game about memes and audience pandering; and Bomb Corp, a pixel bomb defusing game. Can be played on a smart phone, tablet device, or computer. It seems like you need a Twitch account to play this one?
Keep Talking and Nobody Explodes - $14.99 - Roy owns this game so all we'd need are the manuals, which can be found in PDF form
right here, then we can help solve puzzles to save his butt from explosions. I'll miss you, dear.
Sid Meier's Civilization V - Base game: $29.99/Complete Editions: $49.99 - If you like marathon strategy games, this is for you. You'll probably want to get the complete edition to make the most of this game though. Other people with the game will get annoyed if you don't have certain DLCs.
Table Top Simulator - $19.99 - A game that can be any other game you want it to be. Especially board games you use to play at your friend's slumber parties or family gatherings.
Some great 4 player games include:100% Orange Juice - $6.99 - aka Salty Anime Board Game. Go pacifist or genocide route, it doesn't matter because that move was so bullshit you and you know it! Riches to rags all because of a loss in battle to a chicken.
Castle Crashers - $14.99 - A cartoony beat 'em up game from the Newsgrounds era of the internet. It's silly and addicting.
Half Minute Hero - $9.99 - A quick, multiplayer RPG to see who's the better hero. Will you actually save the world in 30 seconds?
SpeedRunners - $14.99 - You run speedily across maps with tricky obstacles. Whatever you do, don't get knocked off-screen.
Better at co-op, but can fun for 4 person multiplayer:BattleBlock Theater - $14.99 - A funny platformer made by the same people behind Castle Crashers. The story is great. The voice acting is amazing. The jumps get redonkulous.
The most beautiful times of the yearJune and December are months to be ever vigilant. A lot of popular games are 60-90% off. Civ 5 complete edition becomes $12.50. Castle Crashers and BattleBlock Theater becomes $3.75. There are also random sales spread out through out the year.
Generous PeopleCleric Evelyn has an extra copy of 100% Orange Juice.
Humble Bundle is also a great place to get games and donate to charity at the same time.