I clean my kegs and lines after use with hot PBW/Some other sodium percarbonate based agent. Everything then gets a good thorough rinse to remove the cleaning agent and the kegs/lines get dried prior to storage.
I don't store my kegs with any sanitiser in them, as I'm worried about rust etc. I store them upside down, in a clean cupboard in my garage.
Prior to use they get a wash with dishwashing detergent and rinsed with cold and then boiling water. Everything gets sanitised with steam. Lids/lines/posts etc over a pot of boiling water and I use a karcher steam cleaner to sanitise the kegs and dip tube. I'm able to get the inside of the keg to >90 degrees, which is more than enough to kill any bugs likely to spoil my beer.
I'm also trying to reduce the amount of chemicals I use at the packaging end of my brewing (I know starsan is meant to be food grade, but hey, thalidomide was s'pose to be safe as well).
Probably not the method for everyone as there are a couple of extra steps, but it works well for me and I haven't had any issues with spoilt beer/infected kegs.
JD