I watched Westworld months after it aired, and I felt lonely; no one still wanted to talk about it. Half the fun of a good work of entertainment - a TV show, a movie, a book, even a podcast or video game - is talking about it, studying it, learning more about it. Any good work of art benefits from study, and a bad work of art benefits from laughing at it with someone.
So I opened the same few tabs I open whenever I finish something I love or hate. These sites analyse stories, dig up trivia, and give fans a place to compare experiences, reactions and theories. (Links have spoilers.)
The ultimate site about creative work, covering over 60,000 works including major media such as TV and books, but also fanfic, pro wrestlers, pinball machines, blogs, podcasts, toys, board games and real life.
A work's page gives a colourful summary and lists the "tropes" the work includes: Elements, such as "unreliable narrator" or "breakup song" or "the butler did it", that are shared across multiple works. The Westworld page includes tropes such as "AI Is a Crapshoot" (robots turn against their human masters) and "Colour-Coded for Your Convenience" (bad guys wear black hats and good guys wear white hats). Here's another:
Fluffy the Terrible/Ironic Name: The heavily-armed security strike teams armed with submachine guns full of live ammo ready to burn down any host that goes haywire are called "QA" as in "quality assurance".
Because this particular show has a metafictional theme, it's an especially rich source of tropes. So like many works, Westworld also has TV Tropes pages for "Fridge Brilliance" (the kind of underlying story logic or hidden joke that you only recognise hours later, when you're getting a snack from the fridge), "Headscratchers" (story elements that don't add up), trivia, "Wild Mass Guesses" (fan theories) and "Your Mileage May Vary" (tropes that fans disagree about).
Wikipedia plot summaries could make Citizen Kane sound stupid, but the "Production" section usually has some interesting details of how a film or show came to be. (Westworld has a juicy one.) The "Reception" section is a jumping-off point for reading reviews.
And those terrible plot summaries are a great way to scratch the itch when you really don't want to watch something that everyone's talking about. I burned through several seasons of Lost that way. I know, I robbed myself of hundreds of hours of thought-provoking entertainment, but ars longa, vita brevis.
IMDb's trivia and "goofs" pages are very poorly moderated, so don't trust them, but check them out for fun. Especially the "incorrectly regarded as goofs" section. Here's the first half of a non-goof for the movie Avatar:
The helicopter-like aircraft makes the sound of an ordinary helicopter - this is not correct: High-speed framed propellers produce an entirely different, quite unique buzz-like, smoother noise at a higher pitch. However, we know that they are operating in an atmosphere which is entirely different to Earth's…
The TV reviews at AV Club (Lifehacker's sister site) are far less comprehensive than these other databases, but they're great for TV discussions that only spoil the episodes you've already watched. And because AV Club revisits older shows, you can use it as a companion for '90s hits such as The X-Files. If you don't care for that show's reviewer, you can skip down to the comments from other fans.
Most popular shows, video games, comics and book series have their own subreddit, which usually opens a discussion thread for each new episode and monitors for spoilers. These threads are still fun to read even years later. Real mega-hits have multiple subreddits, such as the main Game of Thrones sub; the theory-specific sub; the Freefolk sub for unmoderated, often spoiler-filled discussion; and the Song of Ice and Fire sub that mostly focuses on the books.
Most popular movies have a thread in the Movies subreddit; here's the Black Panther thread. Discussions of individual books are a lot more scattered, but you can Google "reddit [book title]" to dig some up.
It turns out that SparkNotes works great as a supplement when you've actually read the book. I used it to appreciate the themes of Victorian sexuality in Dracula. And the site covers plenty of contemporary works. If SparkNotes fails you, try Schmoop (which wraps its analysis in cringeworthy slang) or CliffsNotes (truly the thinking person's cheat sheet). For example, while SparkNotes only covers two of Kafka's short stories, CliffsNotes covers nine more.
You could spend weeks, maybe years, reading up on any one piece of entertainment. Hundreds of video games each have their own wiki. Thousands of musical albums are catalogued on Allmusic, Genius and WhoSampled. Franchises such as Pokemon and Star Wars are picked apart in sites upon sites. Shows such as The Good Place spawn hundreds of reviews, discussions, actor and writer interviews, podcasts, and fan works. Every cult franchise inspires fanfiction and fan art. So tell me, where do you go as soon as you've finished something and you need to learn more?