My trusty Sennheiser PXC 250 headphones that I purchased in 2004 are falling apart and it is time for me to buy new noise cancelling headphones.

I want an over ear type headphone that will really do a great job for noise cancelling and it has to be really comfortable to wear for long flights. Also I want a headphone that folds for easy storage in a carrying case. What are people recommending these days?