I have 3 x HK450 (HobbyKing) and 1 Trex 340 Sport (Align). It depends on what you are looking for. The Trex 450 Sport is more responsive (less loose parts), but I still enjoy the HK450's as they are easy and cheap to repair. I learned a lot from them, and I feel more confident with 3D on my Trex because of that. Oh and don't forget a simulator. Costs less to repair when you crash.

I also have an HK500GT on order. Being shipped soon (no more back order parts). I will also be trying the OrangeRX which is supposed to be DSM2 compatible (my DX7).