Hi. I can’t speak to “the best” camera as that is subjective. You want a camera that you are able to fully control manually and that takes interchangeable lenses. I started out with Canon’s Rebel (xTi) and was very happy. The lenses are very important so invest in good glass. I wish I understood this from the onset. A Canon L lens will hold it’s value and you can use it on different bodies as they change and you advance. Nature and wildlife are two different types of photography. Nature generally requires a wide angle lens, or macro. Wildlife requires a longer lenses. Birding generally requires a really long lens. Hope that helps.