Here's a basic argument for a somewhat vague Creator God: the universe exists. Things that exist tend to have causes. Powerful things like superintelligences or transcendent uploads are good at causing things. This universe might have been caused by one of those really powerful things.

I would be curious to know if you are putting this forward as an hypothetical argument for the sake of the discussion, or as an actual summarised argument that you really do find at least somewhat persuasive.