diff -y -W 200 file1 file2
Shows a side by side diff of 2 files with enough column width to see most of what I need usually.
I have actually aliased this command as diffy
ctrl-r
searching bash history
du -sh * | sort -h
shows size of all files and dirs in the current dir and sorts them in ascending order so you can easily see the largest files or dirt ant the end of the list
ls -ltr
Shows the most recently modified files at the end of the listing.
+1 for sed command in the wild