My vote is for the E-Flite Mini Ultra Stik, using the brushless outrunner power system recommended by E-flite. It's not RTF but there isn't a whole lot to do but install your servos and motor. You will have to glue one of the two supplied firewalls in depending on which power system you use. The geared system uses a different firewall than the outrunner.

It's small
It'll cost you about $400
You won't outgrow it.
And you are not a rank beginner with no RC experience.