i like to use flash on my site in the form of a minimal intro.
but i never put it on a page by itself, it is set up on a page with all the links to the material in my site (
http://www.brutalporn.com). the surfer can either stick around and see the intro, or just more on to the parts that actually interest them.
flash can be useful, but i like to minimalise it and retain as much usability as possible in the site.
the biggest problem with flash online is the way it is used, i am sick to death of 'skip intro' buttons. in those cases the flash doesn't really add to the site, and if anything, detracts from it.