Let me give it a try
- Wow, thats so amazing.
- Oh, I wish I thought of that / Oh, I wish I could do tho that.
- Oh wow, Einstein is nothing compared to this...
- Its quite obvious that you thought of that. No one in the world can be so amazing.
- This is skill, baby!
- Can you teach me to do this awesome thingy?
- You really do know how to do your thing, don't you?
- Is it really true, this is only the prototype? I mean, its so awesome already...
Given that you're not only after the compliments, lets do some other kind of positive common things:
- You know, what I like the most is that no animal was hurt in the process.
- I like that color a lot!
- You see, even you can do it.
- I like the simplicity of the whole.
- I bet others will like it too.
- I always have known that you would surprise me one of these days.