I agree, a site that is fully Flash is awful.. a good example of bad is
http://www.citizen.com.hk/index.htm
The navigation sucks .. every page is "Loading..." and on the home page the navigation like rotates.. it's very artsy, but I think confusing for the average (L)user...
Moderation is the key to almost anything (except sex

)...
The advantage of Flash is that the file sizes are smaller b/c it uses vector graphics.. some peeps exploit that so you end up with sites that are Flash overload... like the Citizen's site.
JMHO
oops forgot to say that you can't beat broadband if you do any online RPGs...