We often trash developers who don't keep their GOG versions up-to-date or who charge owners of a game again for extended versions, HD upgrades or who want money for minuscule DLCs.
But there are also developers and publishers who care for their customers, who still patch and extend their games and who give away upgrades and additional levels or DLCs for free.
I think it's time to honor these developers with a GOGmix: http://www.gog.com/mix/games_that_got_addtional_content_for_free_after_release
So if anyone wants to help me with this mix, please write down in thread which games got additional content after release. I'm mostly looking for gameplay content and free major upgrades, but I may also include free soundtracks, novellas, artbooks and similar stuff.
Games included in the mix so far: Among the Sleep Divinity: Original Sin - Enhanced Edition Ether One Redux Outcast 1.1 Shadowrun: Dragonfall Unmechanical Extended Valdis Story: Abyssal City
Quick correction: the old DLC version is still available for those who purchased the DLC version of Shadowrun: Dragonfall :)