Well FWIW, I'd say drive both and then choose. I personally love my 2013 Camaro V6. It's a very nice and fun car to drive. It gets good fuel mileage and looks amazing. I get tons of compliments on it all the time. For sure it's a chick magnet. I also wanted the M6 for mine as I honestly don't think autos are that fun to drive. Then again I grew up on manual transmissions so it's always the first thing I go after when buying a new vehicle.
I managed to snag mine for right at $21k and went after a specific color as well. Black exterior, black interior and black wheels. I've since changed the wheels(now have a Summer and Winter set) but the new ones are black as well(well plastidipped).
I honestly was looking into a Challenger because I previously had a Ram 1500 and knew I'd get a better trade in if I went Chrysler products. However, after getting a close look at the Challenger I wasn't that impressed. Sure it looks good but it also reminds me of a battleship. It just screams huge, and not that it is huge. The Camaro on the other hand, just oozed sexy and sporty. I didn't really care about the performance of the car as I've got another toy to satiate my need for speed. So I wanted something that looked nice, got decent fuel mileage(I get right around 21-22mpg's in City) and was something different than the trucks I'd been driving.
So check them both out. I've managed to put a K&N CAI and Flowmaster axle back on the car and am well pleased with the sound and performance. Only other mod I plan on doing now is a nice dark window tint to complete the black look.
Here's a pic of my Camaro with the C5 wheels:
And here's why I didn't choose a V8 Camaro and will never worry about trying to get a fast car... because they aren't even close