Hmmm... According to LR, my most used combonation is my 5DIII + 70-200 (+/- 2xtcIII) but i blame wild life shooting for that.
I have a random Paul Frank camera bag for day to day use (as no one recognises it as a camera bag http://farm9.staticflickr.com/8393/9016120803_cc9d2c34f1_o.jpg), and usually have my 5DIII + 24L for my day to day life, maybe the 40mm or 50mm too if i feel like it, or put in the 70-200 if i'm thinking portraits.
For wildlife i use a Thinktank Shapeshifter with 5DIII, 500L, 70-200L, 40mm pancake and both TC's
Travel (small) i use a Lowepro slingshot with 5D + 17-40 + 24-105
I don not have a bag for all occasions yet, that is for sure! My thinktank Shapeshifter is not ideal with a big ass lens, although it does fit it comfortably!