I thought I’d never go for a meme in this blog, but…
herttoniemi:ferrix ~
2 $ history|awk '{a[$2]++ } END{for(i in a){print a[i] " " i}}'|sort -rn|head
123 ls
85 df
65 cd
32 ping
26 sudo
24 rm
21 du
17 exit
13 ssh
12 upslug2
The first two lines are really my $PS1. I think my history is a bit b0rked.