When you see the words 'The Best of,' usually thoughts of split tv episodes (how do they decide 'the best' anyway) and selected comic strips from some funny papers comes to mind. It is the same here.
This is the one volume collection of the three volume RBG pokemon manga. It contains all three volumes minus most of the Team Rocket plotline. The only TR story it has is the Mew story with Green (Blue for you Japanophiles). Still a decent book, but definitely not the best. If you can find them, go for the individual volumes. The upcoming Yellow collection will most likely be the same. Hopefully, this is just a precursor to Viz releasing the Gold/Silver series on up in the near future.