Not to turn this into a Best-of-Flash links list, but...
I do Web/Graphic Design and Flash Animation for a living, and by far the best I've seen has come from these folks:
https://www.fantasyinterfaces.com
They recently completed Conspiracy Games site at:
https://www.conspiracygames.com
(CLICK ON EVERYTHING, even if it's closed or inactive)
Pretty cool stuff.
Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS
izzylong.com