I found the Garuda movie disappointing. While I appreciate the effort, the actual movie is quite bad.

I am not aware of good Thai sci-fi movies or tv series. And I hope that this will change in the future since I love Thai action movies. There are so many great action movies such as The Protector, Chocolate, or Ong-Bak. Some of the famous Thailand actors played in big sci-fi franchises. For example, Tony Jaa played in Monster Hunter together with Milla Jovovich. Looking forward to some great Thai sci-fi movies which leverage the local action movie know-how.

Update: review coming soon for the Red Eagle (2010) Thai sci-fi movie.