Watched a few demos not long ago, and came accross a production called Dim by Mellow Chips. It was released at the Assembly party in Finland in 1996, where it got second place in the competition.
I remember that I was not a big fan of this demo when it was released. When I had a look now, I saw it with new eyes and I enjoyed it more than before. It certainly had a ton of different effects, and many of those were enjoyable to watch. The only thing which bugged me a bit was the music, which could have been better.
You can find the demo on Classicamiga.com via this link:
Dim by Mellow Chips
Have a look and please post what you thought about it. I think it's a very good demo, even if I didn't many years ago.