Emacs users will recognize many of the readline defaults -- unsurprisingly, given both are GNU software.

I use "yank-last-arg" most often, which is M-. by default.

  $ mkdir abcd
  $ cd <M-.>

On Zsh, I have M-, bound to "copy-earlier-word", which makes M-. M-, M-, cycle through the arguments to the previous command.

In reading the manpage for Bash, which doesn't have this function, I've just found "history-search-backward", which searches through history to find commands based on what you've already typed. That will come in useful!

  $ bind '"\er":history-search-backward'
  $ bind <M-r>

(Note that M-r is bound to "revert-line" by default, but I doubt I'll use that.)

These functions are all listed, with explanations, in the Bash and Zsh manpages.

Edit: As I see from another comment, a binding for "history-search-backward" to the Page Up key is in /etc/inputrc on Debian and derivatives.

It is also very convenient to remap up/down keys to not just list history, but to do completion based on already typed characters:

    if [[ $- == *i* ]]
    then
        bind '"\e[A": history-search-backward'
        bind '"\e[B": history-search-forward'
    fi

(fix: grammar)

Debian and Ubuntu typically have a commented-out mapping for this in /etc/inputrc as pgup/pgdn that I always enable in my ~/.inputrc. Editline supports something similar in .editrc IIRC.

Funny, I became FreeBSD user because default .cshrc contained it (iirc). I didn't know about shells, readline, etc. back then. Wonder why they do not enable it on up-down by default, cause I see too many linuxoids around bored with up-up-up-enter up-up-up-enter to replay history, not even knowing that completion exists (along with at least ^K ^U ^C).

What's the point to type a half-command and then replace input line with one from history if I press up? That somewhat resembles ugly cmd.exe, which every windows user imagines when someone says 'cli'.

Weird, I'd have thought C-r is the one readline command everybody knows even if they know nothing else abour readline. Almost cannot imagine using command line without it. (Though there's also the "like tab-complete but from history" that I never really learned to use.)

Ah! yes, at this point C-r is so entrenched in my habit, I didnt even realize it might be new to some.

This is the shortcut to first learn when starting living in the command line.

Yes some of these useful functions should be bound by default IMHO. Here are my settings to bind ctrl-{left,right} and {up,down} to more useful defaults. I.E. jump as the shell tokenizes the line, and search history for what's already typed respectively