Rao He Night Market location
Good bobba, tapioca milk tea, pearl milk tea, bubble tea (etc) can be found just about anywhere in Taipei. If you are a major cheapskate (or even a local), you would think NT$70 for a Ten Ren Tea Station drink from a trendy mall basement food court is a blatant rip-off, when you can get a perfectly decent tea drink for NT$30 to $40.
奉茶 or Tea Serving is a fairly new chain that started showing up around 2008 or so. One of their signature offerings is called 霜乳奶茶. It's a cup of rich and flavorful black tea with a thick creamy foamy layer put on top. The cream texture is out of this world, and is rich and sweet (so you probably don't want to have something super greasy before that, and your internal pipes will thank you for that). You can sip it separately with the tea, or mix it in together. The cream has a Hokkaido milk flavor to it, and is unlike anything else I've had.
As of now, I'm sure this drink is no longer interesting. But it's always fun to get. I hear that 85C in Irvine (California) offers a version of this.