gotta agree budget is first... but if you're into the hobby with 15 planes then you're probably not worried too much about budget.

The best RTF heli would probably be the eflite blade 400. That said many people are still spending a lot of money upgrading them so going with a trex 450se v2 (which are quite cheap right now since the release of the trex 500) might not be a bad idea.

Do you have a radio with heli programming that you can use?