Flashblock is not needed on Chrome - go to settings/advanced/content settings/plugins and select "click to play". Now flash will not run automatically. But you can decide to click on something and allow it to play if you want. Works great - no plugin needed.
Firefox differs from Chrome in that it will enable Flash for a whole page, rather than per-element. This means you still need an extension for blocking Flash ads on Flash video sites.
Firefox's model is better, I think. Plenty of sites use hidden flash videos for various utility functionality. How are you supposed to click on these hidden videos so that you can enable them?