Gear: Bags and cases
It is very hard to make a definitive claim that one bag is the "best". There are many options for bags and cases, it really depends on your uses. Here are my favorites, starting with the largest:
This four-wheel roller case is absolutely superb. All the weight is on the wheels and you can easily push it about on most urban surfaces. So much nicer than any other form of equipment carrying. I still keep my expensive stuff in a backpack but the tripods, sliders and lights go in here.
LowePro Flipside backpacks - £70
They are designed to protect your gear from thieves by having the opening on the inside of the bag, where your back is. It also allows you to get gear out of the bag while it's still on you. There are now many similar bags available, but I've not tried the others.
Crumpler Light delight 400 belt pack - £35
I've grown to love this thing. It gets a ton of use for travel, where it holds headphones, travel documents, coins, mobile phone, etc. And I use it to have some important things within reach at all times on almost every shoot. Things like spare lenses, my backup camera, memory cards, batteries, etc. I have also carried my 5D with a big lens in it, and I also use it as an over-the-shoulder "sling" bag sometimes when I'm doing sports.
Very useful. I keep all my little cables, batteries and adapters in here.