With so much kit to carry around, a good bag is essential. I have several (to the annoyance of Mrs C) but they do serve different purposes –
For travel I prefer the rucksack type from LowePro – the designs are tailored for photographers, with easy access to the camera if needed and lots of good security features to keep things safe. Similar styles are available from Kata and Manfrotto
For day-to-day storage at home, and when taking kit out on a job, I prefer an over the shoulder type bag like the ones from Kata, Billingham and Caden.
I’ll also give a shout out here to the smaller bags made by Manfrotto to house pocket cameras, point and shoots etc. These are really well made and have a wide belt loop on the back so you can carry it around easily. I have three of these for my Lomo, TZ60 and Powershot G10 IR cameras.