It's all known that Flash has both advantages and disadvantages.
So, main disadvantage is that full Flash website isn't seo friendly and has slow loading time.
As for advantages, Flash website is dynamic, beautiful, creative and attracts attention. If you don't want to use full Flash, you can only choose some Flash elements: banner, header, map, calendar, buttons etc.
In this thread I'd like to present you some professional Flash Templates.
Have a look at it and say, what do you think about it?
Live Demo: Pets Club Flash Template
Herbal Tea Flash Template