Although it isn’t the number one of the top fountain pens on the list, the Pilot Metropolitan (via Amazon) appears three separate times on the list.  The three different instances of it are the black with fine nib, black with medium nib, then the silver version.  Although I cant prove it, I’m willing to bet that if you combined those three versions, the total sales would surpass the JinHao 250 that comes in at number one.  Quite often I’m disappointed by the other Amazon top lists when it comes to pens because the G2 comes up quite often, but in the case of the top fountain pen list, I think this is great to see since the Metropolitan is probably the best looking and best performing beginner fountain pen out there, not to mention the fact that the build quality seems super solid and it feels great in the hand.  If you haven’t picked one up yet and are looking to either dip your toe in the fountain pen world or even if you are an experienced user and just havn’t tried it yet, you won’t be disappointed.