I have been working with CMS's since 2001. My previous record of most sites built is 5 using Tridion. Number of Umbraco sites built is now 6, and number 7 in the pipeline.
I am starting to lose track of websites I have created using Umbraco so here is a list.
INS
IASSmarts
My blog
Save the rain
Synexus
Your space
Lipoxen
Air tight security
Innervision
Greater Manchester fire
Akcros
Sample Clay
ICON Volunteers