There was an Angry Birds movie released within the last couple of years. It's still extremely popular.

it was legitimately a good movie. I would've gone to see the sequel despite never having played any of their games.

Maybe the IP. But not the game.

How many other video games from 2009 are people talking about today? It's just the nature of the beast.

counterstrike! ..But it too has now been corrupted by DLC/IAP/etc.

I beg to differ. I am not aware of any DLCs. Counter-Strike: Global Offensive is free to play. There are cosmetics like gun skins you can purchase, but nothing gives you competitive advantage in the game.

Minecraft :)

Good point. I guess it's the exception though. Interesting that it probably had similar user numbers for the first few years as Angry Birds but just had a lot deeper and more "creator"-type gameplay.