On 5 November 1995, a gamer called CJayC created the Video Game FAQ Archive. Later known as GameFAQs, the site was a hub for video game walkthroughs and FAQs, and later cheats, savegames, screenshots and so on. And that's what it is today, only it's a lot bigger than it used to be.
While GameFAQs did lose some traffic to the spread of gaming fan wikis and YouTube playthroughs, its collection of guides for older/more obscure games is still very helpful, like when you, say, buy something off of GOG and get stuck. Or dust off your old SNES to play an RPG... and get stuck.
Plus, there's a certain nostalgic charm to those plain-text, ASCII art-adorned walkthroughs.
For example, I used this walkthrough for Albion just last month. Love that mid-90s feel.
GameFAQs itself is celebrating the anniversary by running its third Best. Game. Ever. contest where, from a pool of 128 games, one will be chosen to be the site's most popular through a series of voting battles. If you wanna take part in the voting, or just look at the results, you can do so here.
The ASCII for top pic were made using Jörg Seyfferth's ASCII generator.