I think the most famous artist I remixed back in the day must have been Matt Darey and his rocktronica project Urban Astronauts. (I’m not counting Jean-Michel Jarre and Klaus Schulze as those remixes were actually covers where the artists weren’t involved in the project).
If you know your trance music history you know that Matt was one of the big names. He’s sold more than two million albums during his long career. I used to send him my tracks and he played some of them on his radio show Nocturnal. In 2008 when he was starting the Urban Astronauts project I was asked if I wanted to remix one of the tracks. I got to choose which one. A couple of weeks later Urban Astronauts – Animal (Bjorn Fogelberg Remix) was done and approved by Matt. The EP was released later that year.
https://soundcloud.com/knatter/urban-astronauts-animal-bjorn-fogelberg-remix