I like to build early damage with fizz to get that early advantage and minion count.
Depending on the champion you are versing, Ad, Ap, etc. I would build either Frozen Heart, for Armor and manna (You can't go wrong either way with this item due to the manna and CD boost, making it a good early game item despite the AP of your opponent) Spirit Visage is a great item early mid or late game. It gives a good boost of health, magic resist and Cooldown Reduction.
I always build Black Cleaver, but Trinity Force is a great item to build in it's stead if you feel you would prefer that.