I’m wondering where I can find good collections of dictionaries which can be used for dictionary attacks? 

I've found some through Google, but I’m interested in hearing about where you get your dictionaries from.

Nice list collected by Ron Bowes you can find here:
https://wiki.skullsecurity.org/index.php/Passwords
Other list is from InsidePro:
https://web.archive.org/web/20120207113205/http://www.insidepro.com/eng/download.shtml.
