I'm personally an enthusiast of legacy character encodings, so it makes sense for me to have a page like this.
If anything here piques your interest, click on one of these options to explore what it has to offer.

DOS Codepages
ISO Codepages
Windows Codepages
MacOS Codepages
EBCDIC Codepages
Other Codepages

Currently a work in progress. Amount of codepages included is subject to change.
Data from Wikipedia and Wikibooks (data licensed under CC-BY-SA 4.0), as well as HP.