Related to this, I'm not sure how many people use them, but there are categories at the bottom of every page which group together similar articles, navboxes tha

Related to this, I'm not sure how many people use them, but there are categories at the bottom of every page which group together similar articles, navboxes that list articles that are related, and at the left side of the page "what links here" which lets you find incoming wikilinks. Oh, and on the talk page there are Wikiprojects where you can find categories for projects built around certain areas like Film. Lastly, Wikipedia's Featured Articles are some of its highest quality ones and usually go quite in depth while being well-written and interesting.