One of my favorite things about Reddit is how niche some of the subreddits are. For instance r/TheLetterH exists and it's a community dedicated to, you guest it, the letter "h". Basically H is the best letter and all other letters are inferior, particularly the letter G.
Or on the odder side of things there is an entire subreddit dedicated to Hailee Steinfeld's armpits. So... yeah.
There's also r/ATBGE. Which stands for Awful Taste But Great Execution. And it's things that are made with great expertise but the thing itself is shit. Like a tattoo and the tattoo artist was very skilled but the tattoo is of Bin Laden and Stalin shaking hands.
Or r/BitchImATrain. Which is just videos or images of trains. It's kind of weird to explain but it's just trains.
And you can't forget r/chairsunderwater. Which is chairs under various bodies of water (I.e. pool, lakes, puddles, etc.). But if the chair is not fully underwater the post is marked nsfw. It's kind of funny. Not as funny as you'd think but still funny.
Or how about r/DramaticText. Which is videos of text put to dramatic music like Beethoven. They recently had a big fiasco with a user, u/Burrito_fucker_69. Basically it's like cursed stuff but funny instead of vaguely racist. They had to ban memes about the user because that was basically the whole sun for like a week.
And oh my god I almost forgot about r/fuckpongkrell. Basically a whole +30,000 people dedicated to hating the shit out of Pong Krell a character from The Clone Wars.
Last one I'm going to mention is r/heep. A sub dedicated to posting pictures of shitty keeps with the like horrible jackass mods like this one.