I'd say, for a hardware hacker, one they build themselves. I'm building one right now, have ordered all the parts for relatively cheap and it will be a lot more powerful than a Parrot Drone and gives me more freedom with what I want it to do.
If you could include prices that would be amazing, but I can always look it up if you can just post the parts!
A proper quadcopter is different than those styrofoam quadrotor things you see. A copter will take longer to learn how to not crash, but you have more precise control.
Frame: http://shop.flitetest.com/multirotors/bat-bone-tri-370-kit/ but you can easily build a frame yourself from either wood or aluminum towel holder bars from home depot.
Flight controller: http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idp... I have this one, the 2.0, but there's a 2.1 out now too.
Motors: http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idp...
ESCs: http://www.hobbyking.com/hobbyking/store/__25363__Turnigy_Mu...
Tail servo (don't needs this for a quad): http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idp...
Batteries: http://www.hobbyking.com/hobbyking/store/__9394__Turnigy_220...
Radio: http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idp...
That's all the major parts. You'll need a few odds and ends like propellers, servo extensions, connectors for the battery and ESCs, etc. Hobbyking sells a power distribution board you can use if you don't want to make your own wiring harness.