Mine's a vote for the herbs and spices - get a 7 day pillbox and stick in some herb salt, black pepper, swiss boulllion, basil, tumeric, dried crushed garlic and some thyme. T'is a recipe for success!
You can premix your muesli with dried milk and just add water to eat.
Cous cous has been mentioned already - I swear by it. You just have to boil your water then add cous cous and take off the heat - no more fuel needed. I preseason this before I go with chilli etc. ad carry s+p to season when done.
I usually take good meat for the 1st night/brekkie then dried stuff for the rest.
I love the planning stages too, getting everything just right. I've just started making some muslin and leather bags to keep it all in to improve the feel over ziplocks.
Agreed re- Muesli and oatso simple and couscous. What about Falafel balls ? Only really need water and a bit of oil ?
Nick