The Esky line of RC Helicopters.
The Esky models begin with the Honey Bee, a 4 channel, fixed pitch electric heli that is a good starter RC helicopter. Fixed pitch means that the main rotor blades maintain the same angle of attack. Lift is increased by increasing rotor rpm. The Esky Honey Bee E004 is a good starter RC helicopter because the response time is a little slower and replacement parts are economical. A beginning helicopter pilot is going to buy a few replacement parts before earning wings.
I started with the Esky Honey Bee. I crashed it several times and had to wait weeks for parts. I was in Iraq at the time. I purchased the CP2 to use while waiting for parts. If I had to do it again I would buy two CP2s. Fly one model while the other is awaiting parts. Having two of the same model heli on hand means more air time and less parts inventory. I built up quite a stock of parts during my time as a student RC helicopter pilot.
The Esky CP2 E005 is the next model up from the Honey Bee E004 which both have a 530mm main rotor diameter. The CP2 uses wood rotor blades and the Honey Bee is a plastic. Many parts are interchangeable between these two. The difference being that the CP2 is a 6 channel RC helicopter with a collective head assembly. That means the main rotor blade pitch is variable. On a collective head RC heli main rotor rpm is kept constant and lift is achieved by increasing the main rotor blade angle of attack. The main motor is the same one used in the Honey Bee but instead of a 7 volt battery an 11 volt Lipo is used. This increases main rotor rpm considerably and gives the Esky CP2 some very responsive 3D capability. The CP2 still has a motor driven tail rotor which means it turns great in one direction and is slow to turn in the other direction. The Esky CP2 is a fine little RC electric helicopter. It is more responsive than the Honey Bee but still the cost of parts is very reasonable. The Esky CP2 is also a good starter RC helicopter.
The Esky Honey Bee King2 E016 and E017 has a 600mm main rotor diameter. It is a larger RC helicopter than either Honey Bee or CP2. The Honey Bee King2 has a collective main rotor head assembly and belt driven tail rotor. The King being larger than the starter RC helicopters consequently has more parts, more servos, brushless motor, larger battery, larger main rotor blades, and larger more expensive everything. This model RC heli is better flown by an experienced pilot. At this model level crashes can start to get more expensive. Of course the point is to fly not to crash. Check Radds school of helicopter flight for RC helicopter flight instruction.
The Esky Belt CP, E0013 and E0014, has a 680mm diameter main rotor and belt driven tail rotor. This is desirable because it removes weight from the tail and the belt driven tail rotor is variable pitch. A motor driven tail rotor provides good turning response in one direction only. Turning in the opposite direction is slow and sluggish. The belt drive variable pitch tail rotor has equal turning control in both directions. 
The Esky Belt CP is a lot of RC helicopter for the price. Get performance that rivals the Trex at half the price.
All the Esky models can be purchased (RTF) ready to fly.