Single-serving sites (SSS — hat tip to @jkottke for coining the term) are some of my favorites.

Here are three I use a lot:

https://systemfontstack.com

https://smartquotesforsmartpeople.com (by @jasonsantamaria)

http://www.its-not-its.info (by @me3dia)

systemfontstack

Webfonts were great when most computers only had a handful of good fonts pre-installed. Thanks to font creation and buying by Apple, Microsoft, Google, and other folks, most computers have good—no, great—fonts installed, and they're a great option if you want to not load a separate font.

@nazhamid @jkottke @jasonsantamaria heh, someday I should buy an SSL cert for that page. Glad it’s still helpful!