When I think back to my days of playing various Valve multiplayer games over the years, the one that really stands out to me the most for being fun to play with friends is Left 4 Dead, and it's really not even close. Left 4 Dead is by far the most fun Valve game to play with friends.

The main reason I say that is because I like multiplayer games involving playing on a team with friends, and feeling like I'm interacting with my team while I'm playing. Like yeah you can run off on your own in Left 4 Dead, but that's pretty dangerous in the game just because if a hunter or smoker gets you, your team will be too far away to save you.

And in Left 4 Dead, you're constantly working with your team to plan what you're going to do to win vs the other team, and the "strongest" way to play the game requires all 4 people on a team to actually work together to attack the other side instead of just doing their own thing individually. So you really feel like you're part of a TEAM in Left 4 Dead.

Looking at other Valve multiplayer games like Counter-Strike or Team Fortress 2... it feels like it's really easy to play those and completely ignore what the rest of the people on my team are doing. When I play Counter-Strike, in like 9/10 games I play people just run off in their own directions, wherever they feel like going -- instead of communicating with their team and deciding what to do as a team. Honestly, a lot of the time when I used to play Counter-Strike I would just turn on a podcast while I'm playing it because there was so little communication with my team that it didn't really cause any problems lol...

It's such a problem with Counter-Strike that I remember a lot of times I would say to a friend hey lets go play Counter-Strike, and then once we're both in the game I would almost forget we're both playing the same game because there was typically such minimal communication and teamwork in the typical Counter-Strike server you join with public players.

Honestly I don't play a lot of multiplayer games these days, but having tried some others like Call of Duty: Modern Warfare 2 (2022 version), the multiplayer experience was generally a lot like Counter-Strike, fundamentally, in that it involved very little team-oriented gameplay. Every round your whole team just runs off to do their own thing instead of working as a team.

Left 4 Dead really stands out as a game that is not only multiplayer but more or less requires you to actually work together with your friends constantly as you play to win the game, and that made it an unusually good multiplayer experience to play with friends.