Wenaptic
By successfully created, I take it you mean games which have achieved a lot of success, rather than just games which developers actually finished making?
To name a few off the top of my head;
Mortar Melon by TheHen has probably had a million or so downloads on Windows 8 (I'm not sure of the exact figure, but it has been well received)
Super Ubie Land by Notiongames had a successful kickstarter, gained recognition from Nintendo and is currently in development for the WiiU.
Both 'No One Has To Die' and Magnetized gained over 200,000 plays on Kongregate in their first month or so of launch which is very impressive work (as most games only get a few thousand).
Squidsters 'Airscape' has been very well received on gaming sites, as have various other games. If you do a search on those game names it'll probably get you a lot more details.