Bayer contour does not require coding, it is simple and reliable however it might not be as small and compact as you would like.
Avivo nano is about as small and compact as you can get however it does require coding whcih is extremely simply to do, just insert a chip into the side of the meter that you get with every new box of test strips.
There are lots of threads on here about meters have A look through the suggested similar posts at the bottom of the page.