Electricity has never been so much fun

Woop, NVM.

You could also add situational items such as Force Staff, Guinsoo's Scythe of Vise, etc. to help the team out.

But besides that, it's a good guide, good job :) +1 from me

Yeah, you are quite right: I moved the BKB in the situational items (build 2).
Maybe I could have placed a "situational" item list in the first build too, but I didn't wanted put them twice, and the first build is more a "Do or die" build so you probably won't have any spare time and gold for anything other than core. :)

Good item choices, and a decently organized guide. The only thing I would change would to remove the BKB from the core extension, to situational, and replaced with the refresher orb. A guaranteed 1200 nuke on the whole opposition is dramatic at any point in the game. I find the style of Zues differs greatly between players, but you will not need a bkb every game.