Most of my dotfiles are available here, under GNU Stow control.

Vim is used with the following plugins:

AbolishAbsolute must-have. Possibly it is used not everyday, but when you will, you will regret its absence before. Tim Pope’s creation!
CodeCommMy own helper for writing commentaries for code, for making code review.
CommentaryLightweight easy to use comment in/out plugin. Very simple, small and perfectly working. Tim Pope’s creation!
FugitiveVery convenient plugin for working with code under Git control. It is a must-have for making patched adds. Tim Pope’s creation!
IndentWiseAllows you to navigate by indentation levels. Could be very helpful in many situations where other high level (or low level) motions are not applicable for fast movement.
MarkColourize words with multiple colours. Killer-plugin for understanding code with many similar words.
RepeatMust-have. Just install it and your surround plugin can be "."-repeated. Tim Pope’s creation!
SurroundAbsolute must-have! Probably the most important plugin and the very first I will advise to install. Surroundings... they are everywhere, especially in source code! Tim Pope’s creation!
TboneVery helpful small plugin for integrating Vim with Tmux buffers. I use it very often. Tim Pope’s creation!
UnimpairedCombination of many often used triggers like enabling/disabling of spellcheckers, line formatting and wrapping; often used motions like next/previous file/buffer, patchset, tag, quickfix entry and so on. It is just very convenient plugin combining all of that quicker commands. Tim Pope’s creation!
ViewPortHelpful plugin for dealing with the code that is hard to navigate visually. For example, when there are many duplicate code or just hardly visible separators. That plugin creates scratch buffer with isolated contents of some part of text.
vim-lspLSP client.
tracesHighlight patterns and ranges for ex-commands.
vim-recrecfiles related syntax highlight and command wrappers.

irssi is used with the following plugins:

go.plQuickly go to window specified with /go whatever.
logresume.plShow tail of the previously recorded log when opening new window.
nickcolor.plBeauty colourized nicknames.

zsh is used with the following:

zsh-autoenvHighly modified version of zsh-autoenv plugin, allowing to automatically execute scripts in projects.
zsh-autosuggestionsShow possible suggestion if you do history search. Very useful, because shows immediate effect of Up+CR keypresses.
zsh-syntax-highlightingSyntax highlighting. Very visually helpful.

The following are not dotfiles themselves, but often used helper scripts: