fish

Huge fan of this program, very intuitive right out of the box and so pleasant to work with.

Custom functions are very easy to program once you get the hang of it, and all around the design decisions were well thought out and sensible.

Downright painful when I have to back to using bash.

Much more usable than the standard bash garbage. The only problems I've had are with people assuming that everyone uses bash and then things don't work. You can't paste command line stuff from Ubuntu forums, phone remote control apps don't work because they assume bash, etc.

It's very user friendly and has great default settings, however it's really cumbersome that it's not compliant with bash in some cases :(

The many helpful features make using the command line much easier.