Don't forget Girls Und Panzer
Now, in order to move on from all this talk of Military Moe, I guess it falls upon me, the Nasuverse fan, to sell you on Fate/Stay Night, or FSN for short.
FSN chronicles the 2 weeks of a death tournament between sorcerers known as the Holy Grail War, the objective of such tournament is to chose who will be given the rights to the holy grail, which is not the actual holy grail, but it is called such because it is an object of such magical power that it would allow you to go beyond what regular magic can go and into the territory of miracles, and as such, the grail itself chooses 7 masters by branding them with command spells allowing them to call upon a servant, who at first glance seem to be simple magical familiars, but instead are reincarnations of ancient heroes and legends from across time and space. So basically you could end up drawing Achilles in the magic lottery and playing him like a pokemon card against someone elses ancient hero. To the death.
And Shirou Emiya, amateur magus and average high school student, becomes involved in the war due to a combination of both being in the wrong place at the wrong time and his own desire to continue his fathers dream, a dream that he has taken as his own and that dream is to be a Hero of Justice. and people in universe treat it as ridiculous as it sounds, most of them either taking advantage of him because of it or mocking him relentlessly.
The series itself has gained tremendous popularity in Japan where it has enjoyeda lot of adaptations into both anime and manga as well as plenty of spinoffs in anime, manga and videogame form. as evidenced by your reddit top 10 list it also has a gained quite a fanbase overe here in the west as well, where people know it better as an anime due to the fact that it's not comercially licensed to be sold in the US so a patched torrent or importing the VN and applying the fan patch are you only options so far.
The VN itself is very long (in-game clock of my on trip into FSN clocked me at 2 days and 10-something hours) and it's set up in such a way where you have to read one route in it's entirety before moving into the next route, and read that one to get into the last route, The author has stated that this was done in order to explore Shirou's ideal of being a hero of justice as he progresses thru each route, the first route (Fate) being where Shirou holds on to his ideal of becoming a hero, the second route (Unlimited Blade Works) where Shirou has to struggle to hold onto his ideal in the face of reality, and Heavens Feel (Third Route) where Shirou has to choose between the his hero dream and reality
The sincere biggest problem that FSN has is the writing, the world is interesting, the characters are nuanced and deep, whether they are servants or masters, and the story is a good mix of both your typical anime tropes (Let's just say Shirou has enough stubborness and determination to give Goku pause) and urban fantasy (Everything has to remain hidden from the public eye, lots of normal people die in "mysterious gas line accidents", etc) but the writing is.... let's just say Kinoko Nasu needs an editor, if he has one, he needs another one on top of this one, his pacing is weird, at times moving fast and others sitting us down for hours while a character provides exposition, his prose is so purple I once saw someone describe it as "practically grape flavored", and he overexplains too much (it's not rare to see the same explanation happen later in the VN, with just a few words swapped here and there) At his best, he can draw you in and tell you an interesting (if long) tale, at his worst? Well... See for yourself.
Avoid the sex scenes unless you want to laugh your ass off, if anything of this seems like too much for you I would turn your towards Fate Zero
The anime prequel to FSN and to the recent FSN adaptation by Ufotable
which takes the Unlimited Blade Works route straight up unlike the old anime adaptation that tried to bled all 3 routes turning it into a hard to follow mess.
It's also worth noting that FSN is part of an extended universe of work the fans refer to as Nasuverse, many of Type Moon works take place in the same universe like Tsukihime (Vampire story) Mahou Tsukai No Yoru (Shortened to Mahoyo, sorta prequel to Tsukihime) and DDD (Deals with demons in the setting)
This is what you need to know if you're willing to brave the murky waters of Nasuland, Personally I like Tsukihime more than I do fate, but Tsukihime is old, old enough that people who where born in the year it was released are probably bumping uglies right now, remake is in the works though.