But if I read this question then I ask myself: What is the best indie engine to create a good PC game, to use the PC platform perfectly? From my experience, Unity is not that bad even on PC. It uses a lot of techniques to render big worlds, better than many other engines. But still it can not mess with UDK, where you can use even bigger worlds and bigger textures and more lights and whatever. So is UDK the best PC development platform? It is also cross-platform. Theoretically there could be an even better solution if it would concentrate only on PC and use DX11 at its best. But there is not such an engine and also Gamestudio does not even try to become the most advanced PC technology available.

So actually everything is just a second best solution.