archive.is is very nice, but they're a URL-shortener as well, so their links are utterly opaque strings of alphanumerics, whereas the Wayback Machine preserves

archive.is is very nice, but they're a URL-shortener as well, so their links are utterly opaque strings of alphanumerics, whereas the Wayback Machine preserves both the full original URL and the date and time it was captured in the archival URL.