I try to build like a tank w/ some ability power items.
I started w/ the recommended items at first but realized I wasn't getting a lot of kills and was being targeted first due to my massive ult and I would die before it even finished!
So that is why I thought tank like, I'm not saying its the best build but works for me so keep the negative comments to yourself.
I choose teleport bc its good for tactics defense and offense wise as far as getting towers. Lets face it, kills<Towers. That's where victories happen kills should just be stepping stones.
Late game items are based on a decent score and more than likely a longer game than normal (50mins+)