An easy way to find out what you should do, can you script well in C or Java?
if the answer is yes - Unity (my recommendation, never tried Cryengine seriously)
if the answer is no - stick with Rad and learn Angelscript, at least you'll be able to do something whilst you learn, you'll be able to do exactly nothing in another 3d engine without this skill.
Also consider 2d engines to increase your skill levels in a less complex manner, some of them are scriptless like RAD can be.
And the graphics thing...on the whole its not RAD, its the users (not directed at anyone, just generally), yes Unity/Cryengine are capable of much better graphics, but not by magic, by the same methods as RAD, there is just more scope (look at Borek's work or Dan's Tron game to see how far you can go in RAD, are you there yet?)
Yeah even I think that i've not pushed 3d rad to it's limits. I know a bit of angel script, and a bit of C# . i've tried unreal engine 3 but it was too. i dont know advanced like not difficult. the answer is complicated. so i'dont have any idea unity always tells error while compiling even when I delete all the objects. so I was fed up. I dont know what should I do . as per 2D games The first game I made was 2D plat former made with Clickteam Fusion 2.5 still sometimes i use it. what to Do???
If you can use C# I wholeheartedly recommend Unity, the compiling thing I'm sure we can resolve.
What sort of games do you want to make & what do you want out of an engine? answer these and you will be a step closer to a decision, for instance I moved from RAD as I wanted to develop for Android so picked Unity as it did everything I wanted.
A move is never easy though, you will be back to square one for a while, I spent weeks just trying to make a cube move in Unity before it clicked with me
I would suggest that if you were to change game engine you should have a clear and specific reason why.
There is no point moving over because you think the grass is greener on the other side. Learn UNITY (or whatever game engine you wish to persue)on the side and decide later. Don't make decisions you will end up regretting.
A community project would be awesome, no doubt in anyone's mind. Regarding a game engine, if there is no specific goal...then don't reinvent the weel. Large companies such as UBISOFT extensively change UNITY's source code and ad extra feautures to suite their needs.
Yumish, modding a game engine would seem like the right approach. But lets be honest here, with todays technology we no longer need to mod game engines except in extreme cases.
I don't know brah nowdays, "I was fed up by the frustration so this whole week or month i've decided just to play Crysis and Minecraft or any other games" I may change my decision I don't know any other good engine???