I really don't care what shell I use as long as it's POSIX compatible, so I just go with the default, which means either bash, ksh, ksh93, FreeBSD sh (which I think is an older version of dash?), or zsh. (I use a mixture of Linux/FreeBSD/OpenBSD/Solaris/macOS, and occasionally other systems as well).

I have some semi-elaborate dotfiles that work with every shell, but each shell uses different startup files, some shells don't have a distinction between login and interactive, etc, so I made a single idempotent config file that sets everything, and every shell-specific config file just sources that (which means some shells will source my config file twice, but that's ok).

Worked well for me for the past ~15 years.

If anyone cares: https://github.com/4ad/dotfiles