These are my go to games for larger groups:

• Codenames: A modern classic! Works best with 6 or 8 people.
• Decrypto: For a more gamey version of Codenames.
• Wavelength: Fun party game that spikes interesting conversations
• Concept: Don't play to win, just play to have fun guessing

I really like 7 Wonders, for 3-7 players and one round is also not too long with about 20 minutes ^^

Quest, which is an evolution of Avalon. It's a quicker game, because the voting phase has been eliminated. Instead, if the evil team win, the good team have a final chance to find the bad people. If you do play this game, I highly recomment playing with the "Director's Cut" rules. It can take 4-10 players.

Libertalia can go up to 6 players, and it's one of my favourites. I slightly prefer the new Winds of Galecrest version from Stonemaier Games, but any version of this game is fine.

Another game I'm on the lookout for is Feed The Kraken, which seems to be an improved version of Secret Hitler, but with a pirate ship.

If you want to end up hating your friends - The Resistance. I love it but it definitely is not for everyone.

For us:

• Bang!: spaghetti western with secret teams, up to 7 players
• Fuji flush: easy card game, up to 8 players
• Exploding Kittens: silly cards where drawing may make you lose, up to 10 players (with the expansion)
• Secret Hitler: a kind of werewolf where you have to create governments and pass laws, up to 10 players

Deception - Murder in Hongkong - for up to 12 people

Ethnos - area control/ set collection/ push your luck with very short turns; hard to get to the table with my group because of the art, but once we play, everyone liked it so far

Cosmic Encounter - classic game with a lot of diplomacy

https://boardgamegeek.com/boardgame/18/roborally - chaos & mayhem, aka. a lot of fun; can drag a bit if players don't get the mechanics

At 6 players we mostly switch to party games.

• Just One is by far our favorite, works great with all sort of crowds.

• Secret Hitler is another we tend to play, doesn't work well with the more casual folks.

Always interested in expanding this list, it's hard to find something outside word games and social deduction that don't have a ton of downtime.

A good question and an interesting thread. At five, our group sometimes tries a substantial game like Viticulture or Power Grid. Knowing the game is critical, however, since many complex games are not at their best with five players. When our group hits six, we've recently been playing Mysterium, which is an excellent, simple investigation game with evocative art and a great deal of replay value. It's surprisingly accessible for new players.

With even larger groups, we sometimes play Mascarade. This Bruno Faidutti social deduction game is similar to his later Citadels, but easier to get started with. Another hit has been Bohnanza, although its wheeling-and-dealing style may not appeal to quieter folks.

When we have players who are easily overwhelmed by lots of rules, we tend to fall back to Sushi Go. This is entertaining enough--though beware of playing it with hate-drafting Magic players.

EDIT: It's "Mascarade", not "Masquerade".

For larger groups, we've had success with these:

Diamant

Bang:The dice game

Citadels

Skull

CamelUp

Just One

Fake artist goes to New York

Sushi Go:Party

Catan has an expansion that supports more players. It makes the game longer, but I personally enjoy the change of pace.

Otherwise, there's plenty of good suggestions on this thread already. Those that are of similar(ish) complexity and that I also enjoy:

• Bang! (Has player elimination, so make sure your friends are okay with sitting out for part of the game)
• 7 Wonders (Turns are taken in parallel, so much less down time. Great if you have slow players.)
• Sheriff of Nottingham
• Codenames (It's marked as 2-8 players, but realistically, you can play with as many as you want.)
• Concept

With larger parties, you'll often be waiting for that last person to arrive. Some simpler games if you want to fill that time:

• Coup/Complot
• Sushi go (Good warm-up to 7-Wonders if your group is new to the game)

Blood on the Clocktower, but you kinda want 8 to 12 players for that.

We default to Munchkin when nothing else seems obvious. Games get long with 7 or more people because someone can always sabotage the leaders victory. But the game is still hilarious and gleefully fun to us after all these years.

It's a Wonderful World (up to 7 players with the expansion )a kind of 7 Wonders with resources and combos. Actually, we don't play 7 Wonders anymore.

Condordia Venus (up to 6 players) very euro-style, move your workers on the map to build warehouses to gather resources to build more stuff and buy more actions..

Root (up to 6 players) very asymetric strategy game. It's so asymetric that each faction plays a different game.

Demeter and Cartographer (almost illimited number of players) like tons of other roll and write, they are the perfect games when there are too much players for other games and you don't want to play a party game.

Also, lots of games are fine if you add extra players with a few tweaks: Mansions of Madness, Pandemic, Res Arcana..

Cash n Guns - 8 players: Players get to have a standoff with foam guns pointed at one another trying to take out each other either with a loaded gun or bluffing that your gun is loaded to gain the most loot that was gathered from a prior heist.

For 8-12 players, I like Green Team Wins.

Sidereal Confluence is a game that really starts to get exciting at 6+ players. It's not for everyone, but for the right group it's a blast!

For Clank and Dominion we have the expansion to go up to 6 players 7 wonders if we are 5-7 people.

For more people it’s usually more casual/party games with the groups I play with

6 players is usually the threshold where I split into two games, so 5 is usually the mex I look for a game to support. Others have listed some great games in this slot.

One more obscure one Ill add is Veiled Fate. Great twist on thehidden role game, and supports up to 8 players.

I've had four player meets turn into five players a few times. I'd say Hansa Teutonica does great in that situation. It's a game that doesn't do as well at lower player counts anyway, so it all works out.

Scythe has an expansion that goes to 6 or 7, I think. Some versions of Smallworld may as well. Formula D plays 10. Dixit can go high too if you have enough cards.

Our go-tos are as follows!

• Monikers: A silly little game that turns from describing a word on the card into bizarre charades. It's ALWAYS been a hit.
• 6 Nimmt!: Can play up to 10 and I've NEVER seen people get so turned up about slapping down a card with a number on it.

Mysterium - identify the suspect by looking at abstract cards given by a ghost (goes up to 7 players I think; use the original Ukrainian rules!)
Shikoku - interesting movement game, goes up to eight players
Eclipse - epic space exploration and battles, nine players with the expansion (I've never played it nine players, it would probably take about a week and need a banqueting table to put it on)

Big fan of The Resistance, as well as Blood on the Clocktower, though the latter is a bit of an investment. If you don't want social deduction, there's also 7 Wonders and Citadels.

Fifa tournament

Wingspan can scale up to 6 or 7 players.

Werewolf is fun for even more.

The Thing: The Boardgame is a really nice game that works well with larger group (up to 8 people). You are basically playing out the move.

These are the games my friends and I prefer currently:

• 7 Wonders
• Dominion
• Catan
• Anno 1800
• Fallout

• Fluxx

• Codenames

• Munchkin

• and if you'll believe it, most people haven't played in so long that it is usually a huge hit: Scattergories

I love light party games with a huge crowd.

Shadow Hunters is one of my favorites for 6-8 players, it's not out of print but I assume the reprint "Fangs" is similar. Truro is a good simple game, and it stays quick from 1-8 players