Long Runners

[Wolf Kanno]

Inspired by this amusing article (https://www.siliconera.com/siliconera-selects-recent-games-to-play-that-require-a-big-investment/), since some people may be facing mandatory quarantine as the world goes mad, what games would you recommend that last more than 30 hours to fill in that time?

[Spuuky]

Dota 2, which requires probably 500 hours to attain even just a very basic baseline competence. Enjoy your living hell!

[Karifean]

*cough* (http://home.eyesonff.com/showthread.php/173044-Karifean-s-Modern-Guide-to-Ys?p=3701032&viewfull=1#post3701032)

[WarZidane]

Well, the article already mentions a few I'd mention (notably FFXIV, Trails and Monster Hunter), but some others I can think of:

FPS: Apex Legends, if you get into it, is very easy to spend a lot of time in. Even if you're not excited about battle royale games, consider giving it a try, as I hated battle royale before playing this game.
FPS: Destiny 2, which has plenty of content to catch up on if you haven't played it yet

ARPG: Path of Exile, which can be a little rough to get into but if you do get into it, it has plenty to grind. A new league just started, too.

Metroidvania: Hollow Knight, which is surprisingly long for a platformer game (30-50+ hours for a first playthrough if you explore everything, depending on your skill). As far as modern sidescrollers go it's fairly challenging but nothing too extreme.
Metroidvania: La Mulana, which technically isn't that big but it takes a long time to complete just because of its difficulty. Not combat difficulty, mind you, but puzzle difficulty. The game has a reputation for its sometimes extremely hard puzzles/riddles.

As a bonus, these are all either free to play or pretty cheap. (Or in Destiny 2's case, a good chunk of free to play, after which you'll have to buy the expansion)

[Fynn]

Well, everyone knows what I’m gonna suggest ;) I’m just gonna add that you shouldn’t just limit yourself to the Witcher 3 - start with 1 and work your way up. Ideally, start with the books before that!

[Sarisa]

I'm pretty sure the 30 hour mark is easy to hit with most online multiplayer games (Shadowverse, Smite, Tera, etc.) but if we're talking strictly single player games...

Steam says I have 33 hours put into The Letter, and I haven't even finished all the routes or gotten all the achievements. It's a horror visual novel, but as someone who usually doesn't like horror you don't have to worry about it being overly scary. Shining Song Starnova is clocked in at 34 hours; it's a mostly linear idol Visual novel that I found surprisingly enjoyable despite not liking the idol genre much either. Both have free demos on steam if you to see if they're your cup of tea.

There are plenty of console or handheld games that would fit this too. I'm pretty sure most of the Pokemon, Final Fantasy, and Tales of games I've played have provided more than 30 hours of entertainment. My recommendations for each would be Emerald, FFX, and Abyss respectively.

I can vouch that my brother has devoted far more than 30 hours of his life to Shadow of the Colossus, Magic the Gathering, and Super Smash Bros Melee. My sister has spent over 30 hours on League of Legends, and I've also spent more than 30 on Yugioh. We all have pretty different tastes, so hopefully at least one thing listed appeals to somebody.

[DMKA]

Xenogears is great if you don't mind an old-school JRPG with really bad graphics even by the standard of its own era. Story and characters completely make up for that though. It takes well over 30 hours to finish even if you know where everything is. :p

[Jiro]

Crusader Kings II (https://store.steampowered.com/app/203770/Crusader_Kings_II/) is now free-to-play and could provide you hundreds of hours of confusion before it provides you with hundreds more hours of entertainment.

[Wolf Kanno]

While not a necessarily long game, I would say that Death Stranding is a perfect game for our current predicament. I also find it to be extremely relaxing, so check it out if you're getting a bit stir crazy and need something to unwind.