The immensely popular and highly addictive Angry Birds has finally left the mobile market and has become mass market. It is now playable in any flash enabled browser for free, check it out here. You can play in HD, which is recommended for people running the Chrome browser and others who have a decently powerful PC, and there is an SD version for all the rest.
Some Firefox users have mentioned framrate and lag issues while playing the game on either setting, though I personally have had no issue, I would still recommend playing it in Chrome, as the URL even begins with chrome, so it was either funded by Google or the developers are just large proponents of the platform.
Let us know if you have any issues on other browsers.