Now, you will find lots of people that claim scheme is the best programming language. I myself am torn between the caml family of languages and scheme.
Most serious stuff I write in Scheme, and when I got parsack (parsec for Racket) I now no longer have any reason to leave.
I was reminded of a quote saying this kind of question (scheme or caml) is discussing brand of waters while lost in a desert dying of thirst. Although PHP post 5.5 matured enormously, I'm still rooting for a scheme.
Most serious stuff I write in Scheme, and when I got parsack (parsec for Racket) I now no longer have any reason to leave.