I recommend 2advanced.com and xeofreestyle.com (and pixelranger.com) all the time for eyecandy. 2advanced.com still offers the most detail and professionalism in 1 package. Eric Jordan (the owner) even does his own music for the site. Pixelranger.com's owner actually was hired to be part of the 2advanced team.
If you take a look at their portfolio, you'll notice much of the work is similar to each other and they get a lot of flak for it... but the fact is they show what they can do via their own site and if the client wants it a certain way (similar to what exists), then they do it as such. Anyway, I digress... point is, the obvious time and effort they put into every little detail deserves commendation. They know how to make the animation appeal to the eye because all of it flows together. If any of you are hockey fans, check out the
Penguins' Website.
Oh yes, to answer the original question, it would take many months of experience to get up to the level they're at, then you'd have to learn some scripting. Give it a couple years if you have a life. By then, newer stuff will come out... Flash 4 and Flash MX is a world of difference, even though actionscripting exists in both.