The Sandman Presents

Neil Gaiman's The Sandman had two direct spin-offs:

The Dreaming, a monthly series;
The Sandman Presents, some occasional mini-series.

Mike Carey wrote three of the latter:

Lucifer;
The Furies;
Petrefax.

The Lucifer mini-series was followed by the Lucifer monthly series.

It is interesting to see what happens next to several of the characters, eg:

Charlene Mooney still works in the Inn of the Worlds' End;
Lyta Hall joins a Greek Drama group;
Lucifer creates a universe;
Petrefax has adventures in the alternative world that he entered instead of returning to the Necropolis after leaving the Worlds' End.

The stories can literally be extended indefinitely.