Zsh has quite a nice option "auto_cd". If the first word you type doesn't resolve to a command, it tries to change the current working directory to it instead. So just typing ~ will get you to $HOME, and .. will take you up one.
I love this option. I type "/tmp" when I'm about to create some short-lived scratch files. Those saying "you can just alias that" are missing the point. Where do you stop with the aliases?