The TenRen chain from Taiwan is known for its consistent quality and standards for tea. I highly recommend after your stop at TenRen's Tea Cafe at 75 Mott Street you walk two doors down to 79 Mott Street to TenRen's tea shop. This is what TenRen is known for worldwide.
An asian stlye teahouse in a sea of english teahouses. All in all a peaceful and pleasant place to spend an hour or two contemplating tea and good conversation with friends.