All in one SEO is good and will give you everything you need as far as SEO is concerned. If you are looking for a simple plugin that will give you an SEO boost, this is perfect. Definitely the one I recommend for beginners.
Yoast has all the SEO features of all in one, but it also has a lot more advanced customization features like editing your robots.txt, creating sitemaps, breadcrumb custimization, etc...It can be used by beginners, but it has a little a bit of a learning curve. If you learn how to use it, the advanced customization features are really great.
I personally used to use all in one, but now I use Yoast only, but if you are just starting out or want a simple SEO plugin, all in one will get the job done.