Keep up the good work.
Top-notch! Much better.
That's great! What neat work.
Right on! My goodness!
Great work! How impressive!
I am so proud of you. You're on the right track now.
Wonderful! That's clever.
Fantastic! That is certainly one way of looking at it.
Super-Duper! That's a good point.
You make me proud! Superior work!
How about that! Exactly right!
Far out! Now you've got the hang of it.
Super work! That's an interesting way of looking at it.
Wow! That's the right answer.
You've got it now. High quality!
Star quality! That's coming along nicely.
State-of-the-art! Top-of-the-line!
Nice going! Out-of-this-world!
Out of sight! First class!