Oh, me too. I was obsessed with Fractint when I was a teenager - It's what got me into coding. Wrote some Pascal that morphed one IFS pattern into another & was soooo pleased with myself :-)
Fractint was one of a number of programs that were very popular for a period because they really showed off graphics cards that, for the first time on consumer hardware, could display reasonably high resolution graphics (EGA then VGA).
There's some fun to be had with the Java based jwildfire these days, http://www.jwildfire.org/, although arguably it's a bit more focussed on making things pretty.
Playing with Fractint and reading Chaos shaped my world view more than most things in my youth. It formed the basis for what passes for spirituality in me.
I became obsessed with IFS (iterated function systems) a looooong time ago. Take a look at the colage theorem and try to make your own ;-)
Cheers