Noble. I will probably lose. In fact I hope I don't make it very far.
Why? Because one of the least realistic aspects of civ is that the player knows a lot about the future: what upgrades to what, what resources will appear, etc. So, in a way, the most satisfying and realistic games are the first few played, where the future is unknown.
I want to preserve that feeling as long as possible. So I'll play at the middle level that I think I'll eventually be able to do well at.