[xymostech]

I use fish. It's pretty fun to use. It has some pain points (most notably missing things like subshells and inline variable exporting) but it's in beta, so we'll see where it goes. I love the completions though, and it's definitely worth checking out for those alone.

[andrewvc]

The subshell syntax is there, it just looks different. Instead of: echo `mycmd`. It's echo (mycmd).

[omaranto]

I think you're getting your terminology mixed up: the bash man page calls what you described command substitution. Launching a subshell is something different and in bash it is done with parenthesis.