I've gone through maybe five or six of different systems, in addition to some pocket cameras, since I bought my first SLR in 1990. In 2003 I got my first DSLR (a Canon EOS 300D) and haven't touched ordinary film since then. I used Canon EOS cameras until August 2011, when I traded it all for a Micro Four Thirds (MFT, m43) system. I haven't looked back. Currently I think m43 offers the best compromise between size, weight and image quality, at least for me. M43 cameras and lenses, are significantly lighter than traditional DSLR:s, while giving up very little in image quality. In 2013 I got the Olympus EM-5, which really is an excellent still photography camera. It is not as good on video, and therefore I still kept my Panasonic GH2, which really is an video excellent camera.
The gear is generally carried in a Lowepro Photo Sport 200 AW, an excellent camera backpack made for action sports. The gear fits fine and is well protected, and only takes a moment to retrieve the camera without removing the backpack completely.