The only time I came close to contributing was for Obsidian's Project Eternity. In the end I didn't chip in because I got the impression that they had absolutely nothing really planned and wanted money based on the fact that their company had made a couple of great games a long time ago.

I also doubt their ability to carry a project to the end. People love to blame the publishers for all of Obsidian's blunders lately, but you can only do this for so long before it starts getting suspicious. The common denominator of KotOR 2, NWN2, New Vegas and Alpha Protocol (all of which were notoriously buggy/unfinished) is the developer, not the publisher.

Twice. Once for Project Zomboid which got me into the Alpha and beyond with constant updates. A great little irometric game that I dip in and out of occasionally and for the few pounds it cost was a good investment. The second was for the new Wing Commander project.

Additionally on the subject of donating to random people, I have also donated to the upkeep of a clan server on a couple of occasions some years ago and also donated to a clan surprise fund for one of our members who'se graphics card blew and he couldnt afford a new one, so we clubbed together and bought him one. Im no longer a member of said clan though and it was some years ago.