I'd say it depends on which languages you already know/have been exposed to.
After downloading some software written in Haskell this week, I installed GHC and got some books on Haskell. Got sick of constantly hearing about how cool it is! After reading a few dozen pages, I thought it looked a lot like (Standard) ML, which I got into a couple of years ago. So I googled differences between Haskell and ML, and they indeed sound not-so-very-different. So I gave up on that idea for now. I was after a language very different from any I knew before. Maybe next year. (In recent years have gotten into Lisp, Prolog, Forth, ML, Tcl etc - each totally different from each other and from languages I knew before.)
A language that doesn't affect the way you think about programming is not worth knowing. - Alan Perliss