Going down the Reddit rabbit hole, here are 7 hopefully interesting subreddits that you didn't see before. All of those are focused in content rather than user made histories, like relationships and etc, there is a lot of subreddits with specific good content and we tried to find some of those, maybe we did it, maybe not, although there was an effort to not put way too famous subreddits, some still sneak on the list.
r/crappyoffbrands: CrappyOffBrands is for products that attempt to imitate another brand, in some odd ways. This includes toys with interesting "crossovers", local stores with a brand name alluding to movie names and even generic fake Shrek movies, perhaps all of us already saw one of those products at some point.
r/BrandNewSentence: BrandNewSentece features new sentences created by the philosophers of the world wide web, every post shows a combination of words never seen together before, and in a practical use, maybe you could see a post that you made in there.
r/HolUp: Holup is for things that seems to be alright for a moment, and then suddenly you notice something very wrong, be it a picture, text or meme. You can always expect some twist of events while browsing posts from this subreddit.
r/TerribleFacebookMemes: TerribleFacebookMemes is for generic style Facebook memes and posts, with minions and hello kitty, and also some dumb things that spread around.
r/AssholeDesign: This is a very famous subreddit actually, but it should be in the list, AssholeDesign mostly shows designs that are made to exploit the user, like fake advertisement, apps with bad practices, straight up scams and more company tricks, it is good to have it around as it puts the spotlight on marketing strategies made with bad intent.
r/PlotHoles: PlotHoles applies some logic to movie, books, games and any plot you can think of, showing how some story could have been solved in an easier way or it is based in a total weird premise.
r/AntiAssholeDesign: As the name implies, this subreddit takes the opposite side of AssholeDesign, it shows good practices that are made for the benefit of the costumer, that sometimes are very creative.
If you didn't like any of those, you could perhaps try your luck at r/random.