Chatime is the best place to get your milk tea. In the past i went to easyWay but after one trip to Chatime I was hooked. Now I even drink juice from them. Only Chatime I have tried so far and I was impressed.
I've been to Chatime a few times now, the milk tea is great. My personal favourite is the Caramel Milk Tea, closely followed by the Chocolate Milk Tea. The menu is massive, including some really weird things, like tea with little bits of potato in it.
The stores are conveniently located, they're all over the CBD and in many suburban locations. My only gripe is the prices, $4.20 for a small drink is a little expensive.