And I can't remember the options to save my life - and that man page, just goes on and on...
My cheat sheet is 99% of the important ones:
I'll add explainers and examples in a follow up.
--archive -a archive mode; equals -rlptgoD (no -H,-A,-X)
-r, --recursive recurse into directories
-l, --links copy symlinks as symlinks
-p, --perms preserve permissions
-t, --times preserve modification times
-o, --owner preserve owner (super-user only)
-g, --group preserve group
-D same as --devices --specials
--backup -b -- make backups into hierarchy at indicated directory
--backup-dir -- make backups into specified directory
--delay-updates -- put all updated files into place at end of transfer
--delete-delay --delete-after -- receiver deletes after transfer
--force -- force deletion of directories even if not empty
--ignore-existing -- ignore files that already exist on receiving side
--inplace -- update destination files in-place
--itemize-changes -i -- output a change-summary for all updates
--max-delete -- do not delete more than NUM files
--max-size -- do not transfer any file larger than specified size
--munge-links -- munge symlinks to make them safer, but unusable
--one-file-system -x -- do not cross filesystem boundaries
--partial -- keep partially transferred files
--prune-empty-dirs -m -- prune empty directory chains from file-list
--dry-run -n -- perform a trial run with no changes made
--whole-file -W -- copy files whole (w/o delta-xfer algorithm)
--sparse -S -- handle sparse files efficiently
--preallocate -- allocate dest files before writing
--remove-source-files -- sender removes synchronized files (non-dir)
--compress-level=NUM explicitly set compression level
--filter=RULE -f add a file-filtering RULE
-F same as --filter='dir-merge /.rsync-filter'
--human-readable -h output numbers in a human-readable format
--progress show progress during transfer
-P same as --partial --progress
--bwlimit=RATE limit socket I/O bandwidth
--append append data onto shorter files
--append-verify --append w/old data in file checksum