I use 2 cables and 1 adapter regularly. Never had any of them replaced. 1 Lightning Cable came with iPhone 5 (pur 10/2012), the adapter was bought a day or 2 after I bought my iPhone 5, and the second cable was bought a few months ago so I didn't have to unwrap on of the ones that came with my other devices.
What I do have problems with are the EarPods. Great sounding earphones, but the right channel always goes out on me every now and then. Some have lasted me months, others only a week or two. I don't abuse them either.