Bard Itemization: So many options!

I love Bard. The noises, the ult, the floating weirdness. Its so fun. I hate chimes but you can't love someone totally. Anyway, building his items are all over the map.

According to http://www.leagueoflegendsmath.com/itemop.html, I should build him:

Champion.gg says his most successful item build is:

I personally build him:

(I start the game with Banner, but then sell it for Portal)

Obviously these aren't close. I'd love your thoughts and feelings on things.