Heads up! This post was written in 2009, so it may contain information that is no longer accurate. I keep posts like this around for historical purposes and to prevent link rot, so please keep this in mind as you're reading.
And by better, we can pretty much agree that Flash can do smoother animations, higher level programming, awesome 3D stuff...the list goes on. In fact, you can make an entire website out of pure Flash if you so desire, and it will look exactly the same in every browser. Why use anything else?