I started my career using ksh93 on Solaris back in 1999 so it seemed fairly natural to transition to bash when I started working in the Linux environment. I love its stability and programming in it didn't seem too bad.
It is challenging to change to a new shell when all of your scripts, profile aliases and functions work just fine in your current one.
I have also tried zsh, but haven't spent enough time learning how to configure it. However, after reading this article Fish looks pretty interesting.