Warframe is now the perfect game. (At least for me)

You should try out Rainbow Six Seige.

Try fallout 3,NV,4 for single player with mods from nexus and bethedsa net. For multiplayer try dying light.

If you haven't played Skyrim yet, you're missing out on the RPG of the decade.
If you have a toaster, Terraria is the best option.

SAS Zombie Assault 4 is a great game to use KongHack on because with the hacks provided, it makes the game more fun and interesting, so feel free to check it out some time!

There are a few that came with Twitch Prime that I really enjoyed, like Tokyo 42 and High Hell. They're both shooters about drugs. Tokyo 42 is top-down and has an interesting story. High Hell is first person and good for wasting time, but it won't really do anything for your life.

Oxenfree is an amazing story-driven side-scrolling semi-horror rpg walking simulator (and if you think that's too many hyphenated terms, you're wrong) if you're not looking for gameplay so much as an emotional rollercoaster. The studio that made Oxenfree is also working on another, similar game called Afterparty, where you're in hell with your best friend and you have to out drink Satan.

Borderlands is my favorite franchise of all time, and if you've never played any of them, I strongly recommend that you do so immediately.

Dishonored and Bioshock are also up there, and both are definitely well worth your time.

Little Big Planet is a lot of (mostly) non-violent fun. It's a 2.5D platformer that has both a campaign and a very large supply of community-made levels. It's basically Super Mario Maker but with fewer restrictions and way more character customization.

With the exception of co-op Borderlands, Little Big Planet, and Bioshock 2's multiplayer, all of the games I've mentioned are single player. If you're looking to have some fun with friends, go for some good ol' TF2 (in spite of the now awful matchmaking).

Edit: Read further than the title of the thread and found a lot of info that makes a lot of what I said useless to you. Sorry about that. I will recommend a few more things, though: Transistor and Bastion. They're both pretty cheap, pretty fun, very interesting, very very good, and accompanied by my personal favorite soundtracks for anything ever. 

One more thing: The Adventure Zone. It's not a game, but it sounds like it's everything you're looking for. It's a D&D podcast hosted by three brothers and their dad that, over the 69 episodes of season one, will put you through every human emotion (but mostly joy).

Invest some time into Space bound.