I'm the opposite. I used to say to myself I only play and support completed games. That went out the window though, as these games take years to complete so why wait so long
Usually I go for games with at least three substantial updates. What I really do not like are small demo versions. Just frustrating to play if it is really well done.
If the description sounds good without being vague, I jump in on the first release. If the write-up is lackluster, vague, or sounds like 5 other games, I wait for the version 0.03. By that point the dev usually knows if it's something they want to stick with or if they got bored/frustrated.
If it's a developer who has completed several games before, I'm willing to start with the first version. However, if it's a new developer, I'll usually wait for 3-4 updates.