I use Firefox all the time and I am very happy that Firefox coupled with the Flashblock plug-in has improved my online experience tremendously. However, Safari is still the default web browser on all new Macs sold. As a public service for the Mac community, I searched for a plug-in for Safari that would suppress loading of Flash animations. There were some shareware plug-ins out there, but I found a great freebie that does the job just fine, and another that isn't so great.
If you use Safari and are tired of those annoying Flash animation, I recommend that you get SafariPlus. Installation is a somewhat simple matter of (1) creating a folder called InputManagers inside your Library folder - if you don't already have an InputManagers folder, that is; (2) moved the SafariPlus folder, in its entirety, into the InputManagers folder. That is it. Not as simple as how Firefox handles plug-ins, but not too bad either. Start Safari and now you have the extra menu item called SafariPlus under your Safari menu. SafariPlus started out as a cookie manager but I won't get into that. Select the new SafariPlus item and go straight to the animation page. I strongly recommend selecting Never, meaning don't allow Flash anims to be loaded at all. Instead of the ads, now you will have just a placeholder, like that in the screenshot. If you really want to see the ad, just click on it. Or Ctrl click it and choose Rewind or Play.
The other Flash plug-in for Safari that I came across works but getting it to work is just too much... work. You would have to create a filter, supposedly for the various web sites you come across. I started doing so but after the fifth one or so I concluded that's just too much work. I think I managed to achieve a quick result by making a filter called *.swf*, which means any web links that contains .swf, the default extension of Flash file, would not be loaded. The star or asterisk ( * ) in computer lingo means one or more characters. So, http://www.blah.com/cool-stuff.swf , or http://www.bleah.com/yada.swf ?=sksksk,foo=kwkwke, etc. would all be prevented to have the Flash file loaded. It seems to be a good solution, but I think the average user shouldn't be expected to know that much.
So, plug that SafariPlus into your Library/InputManagers folder and your Safari experience will be much more enjoyable. The plug-in is freeware but the author John Chang noted that should you enjoy it, give something back, whether by doing some volunteer work, give away an app you wrote, or give him some amount of money, so take your pick of the way you want to give back.