On creepy, my Mac:
2 ~$ uname -a
Darwin 10-8-13-196.isilon.com 9.2.0 Darwin Kernel Version 9.2.0: Tue Feb 5 16:13:22 PST 2008; root:xnu-1228.3.13~1/RELEASE_I386 i386 i386
3 ~$ history|awk '{a[$2]++ } END{for(i in a){print a[i] " " i}}'|sort -rn|head
122 ls
89 cd
43 sudo
19 ssh
18 df
16 man
14 rm
11 mv
11 less
10 ifconfig
4 ~$
And on spooky, my Ubuntu box:
jlasser@spooky:~$ uname -a
Linux spooky 2.6.24-16-generic #1 SMP Thu Apr 10 12:47:45 UTC 2008 x86_64 GNU/Linux
jlasser@spooky:~$ history|awk '{a[$2]++ } END{for(i in a){print a[i] " " i}}'|sort -rn|head
139 ls
121 cd
37 less
32 cat
23 ssh
23 grep
20 sudo
19 find
10 telnet
9 rm
jlasser@spooky:~$

Much of what I do on these boxes is reviewing logs from various Isilon clusters, which doesn't result in a lot of interesting stuff. The rest of what I do is largely launched via GUI (e-mail, Web browsing, instant messaging, and work tracking with VoodooPad) or local workstation administration.