SplitJoin - easily split up things like ruby hashes into multiple lines or join them back together. Try :SplitjoinJoin and :SplitjoinSplit or use the bindings sj(split) and sk(unsplit) - mnemonically j and k are directions down and up
tabularize - align code effortlessly by using :Tabularize /[character] to align by a character, or try the keymaps
yankring - effortless sanity for pasting. every time you yank something it goes into a buffer. after hitting p to paste, use ctrl-p or ctrl-n to cycle through the paste options. great for when you accidentally overwrite your yank with a delete.
surround - super easy quote and tag manipulation - ysiw” - sourround inner word with quotes. ci”’ - change inner double quotes to single quotes, etc
greplace - use :Gsearch to find across many files, replace inside the changes, then :Greplace to do a replace across all matches - made lightning fast with Silver Searcher
vim-markdown-preview - :Mm to view your README.md as html
html-escape - ,he and ,hu to escape and unescape html
Gundo - visualize your undos - pretty amazing plugin. Hit ,u with my keymappings to trigger it, very user friendly
vim-indent-guides - visual indent guides, off by default
color_highlight - use :ColorCodes to see hex colors highlighted
change-inside-surroundings - change content inside delimiters like quotes/brackets
rspec.vim - used for color highlighting rspec correctly even if specs live outside of spec/ (rails.vim doesn’t handle this)
Ag - use :Ag to search across multiple files. Faster than Grep and Ack.
vim-session: use :SaveSession and :OpenSession to come back to your saved window layout