Honestly, there's probably a ton of LitRPG out there.

Look up Sword Art Online. It's not LitRPG, it's a Japanese LN (light novel, their equivalent to YA (young adult) fiction). It's also an isekai, which directly translates to "another world," as in, you're stuck there. Like DCC, it's about a group of (10,000) people who are trapped in a dungeon, except this one is a video game. Death in the game kills you IRL, and dying IRL kills you in the game (a lot of loners who lived alone went out this way). The only way to win is if someone (or a party) is able to complete the entire dungeon, of 100 floors, each with a boss guarding the stairwell. No floor timers, floors can be returned to, and plenty of people just find a town and say "this is my life now" and hope their loved ones don't pull the plug.

And that's only the first book. They resolve that in book 1, though book 2 is a bunch of stories that take place during that time (and so is book 8). Later books involve other games with other weird stuff going on.

Now there are over 2 dozen books. They're all pretty short. It's also been made into an anime, with four seasons covering roughly 100 episodes. (Some fans don't like the fourth season, though.) The episodes that have been released only cover about 18 of the books, and the anime is on hold until the next book arc is complete. We're all waiting on season 5 (except for a bunch of idiots who think season 4 will be remade just for them). There are audiobooks for a lot of them, and they come out about 2 a year, with the English voice actors from the anime doing the audiobooks. The main girl was also the player character in Cyberpunk 2077, though she sounds a lot sweeter here. It's fun (on both sides) when she slips into the other voice.

But basically, DCC is the west's first big isekai, though some say the first isekai was Alice's Adventures in Wonderland, the book from the 1800s. Japan has never owned the genre, it just has the most entries. There are other isekais out there, but not all of them have the dungeon element. Alternatively, Japan has a lot of dungeon crawling stories that aren't isekai, like Delicious in Dungeon. That has some of the silliness of DCC, but not so much the urgency.

Oh, there's also the anime Sword Art Online was based on. It's not a book though, it was an original animation, and games have been made. There may be manga (comic books read right to left), but I haven't seen actual LNs for it. It was called .hack//SIGN, the acting is atrocious (both Japanese and English dubs), but it really kicked the party off in Japan in 2001. Very similar to the first arc from SAO, except it's just one guy who's trapped, the others can come and go as they please, but a bunch of them get together to figure out why the one guy's trapped. A couple of them have investigative backgrounds, so they start by looking for people in comas. There's also a mystery surrounding a rogue AI, and an NPC child who won't wake up. It's not good if you're looking for action (or good acting), but the story is worth exploring, it's just they probably could have done it in about half the episodes. All the exposition and world building would have been better if the acting was decent. The visuals and trippy music are neat, though. But again, it's watched, not read. If you don't already like anime, it's not a good entry point (though, it was mine).

Anyway, if Japan is anything to go by — and clearly it is — there should be copycat series popping up any time now. Sword Art Online didn't start the isekai trend and was itself based on earlier work, but it was popular and it created a demand, opened the floodgates for a whole bunch more to come out. A lot of them featuring a very similar looking main character. So expect more dungeon crawling LitRPGs that aren't the same as DCC but have a lot in common.