Another interesting, and useful, build is:
Boots of Mobility
Heal/Clarity/Exhaust/Ignite, to better help your early game/Cleanse
Everything else isn't necessary on Zilean.
An obvious non-AP build. It lacks 'til mid-game, depending on game, where it starts proving evident when you're not only beefy, but able to both haste and slow two different players, assuring absolution in a gank. More attack speed, and even things like Tiamat, are good in conjunction with stark's, freeing up someone on your team from getting it, and giving you particularly good ranged harassment.
Just focus on TW and Rewind, then Chrono. (making this very effective much, much earlier.) You lose the early game harassment from 'Bomb, but you gain superior survivability, and insane movement, spell spam and team support.