One not designed just to be easy to use, as opposed to being designed for functionality.
Point is, making a decent game is supposed to require some effort, and it always does, and always will.
Java, for example, was designed for simplicity too.
That the language itself is designed for simplicity is one thing, but having no clear type system (like TorqueScript) or having it so that pretty much everything can cast implicitly to bool, that is another thing (JavaScript, I'm looking at you).
OT: I'd suggest going either for GameMaker, XNA (which can be a bit harsh on newbies though), jMonkeyEngine (for 3D games), or PyGame. I'm surprised nobody mentioned that yet.
byond is a ripoff
i can't make games :/
will try the xna thingy
Just prepare to not be able to do anything until you learn C#.
Just because XNA is Terraria's engine.
As if that was a positive thing.