Minimal .bashrc I use on remote servers and shells which aren't used often.
I configured emacs once, this is what I ended up with (not that I really use it much).
Mediocre regexp-based .patch highlighting, mostly for mailing lists.
Minimal .tmux.conf with clipboard support on macOS.
Minimal .vimrc with no package manager, only using Vim 8+ internal package system.
A more heavy, but still only single file, shell config used on my daily macOS shell.