This, which I found somewhere on zdnet.co.uk sums up my feeling about Flash perfectly:
There's nothing wrong with Flash, provided you don't use it to construct web sites where people want to find information, navigate easily or do anything beyond passively consume exactly what you choose to give them in exactly the way you've decided.
There's also nothing wrong with using it for a splendid splash screen replete with movies, sound and animation — if you don't mind frustrating, annoying and possibly even driving away people who might, just might, have something better to do.
In fact, Flash-based web sites are quite possibly one of the most useful pieces of network technology around. Like heroin or microlights, they ensure that those who think it's a good idea aren't around to annoy us for too long.