ORIGINAL: boss_blueangels
Hands down I'd go with the Challenger. As I'm sure you've read, it's nice to have the prop in the back, so you don't have to replace an engine/prop every time you crash. (which you will... very easy to do. lol) Also, it won't be quite as touchy as the Decathelon as it's much smaller and a scale plane. This plane is a blast to fly, even for an advanced flyer. If you wanna move on to something more aerobatic, this will provide a great foundation to build on. ALSO, it has X-Port so you can attach the aerial drop module (loads of fun!) and the one for dogfighting (even more fun IMHO!) for when you get more used to the aircraft.
Anyway, that's what I'd do. Good luck and let us know what you get!
A very good choice, but consider the new Aerobird 3. You'll eventually desire "the need for speed" with something like a Typhoon, Stryker or Ducted Fan ARF, but you will always find the need to occasionally fly this plane with its X-port accessories.