Vermintide 2 is an absolutely fantastic time, especially with people you know. I’ve actually stopped playing since none of my friends do anymore and I hate randoms. Lacks in variety once you’ve finished it, but it’s fun to pump the difficulty up and get better and better.
Killing Floor 2 is also a great way to go. No wasted time crafting, just time spent shooting. The guns are quite possibly the most realistic (well, the ones based on real world models) that I’ve ever seen in any game ever, and this game has, hands down, the most enjoyable to shoot shotguns of any other game in existence. It is lacking variety, though. Tons of maps, but the games play out the same every time. You shoot waves of zed after waves of zed. There’s a few different bosses, but not enough.
Payday 2 could be a really great one. A lot of the missions have the option of doing stealthy approaches or go in guns blazing. There’s heists, breakouts, etc. so you get a little bit of variety. Plenty of weapons, masks, and skins for the masks to find and try out too.
Borderlands 2, as has been stated, is a great one as well. Though the enemies do often feel like bullet sponges, especially with more than one person. But it’s a decent sized story, it’s hilarious (if you like the low level meme-type jokes), and there’s quite a few viable builds for each different character.
Destiny 2 as well. Can’t really say much for the story (it’s shit), but the game is really easy to just zone out and shoot through with your friends.
Edit: weird, the last post was 3 months ago but this was at the top of the list underneath the stickied posts on my screen. I guess better late than never, eh?