Brew Tea Bar is my go-to place for boba in Las Vegas.
My personal favorite beverage here is the Lychee-Peachy Green Tea. As a disclaimer, I do not really like tea or milk tea, so this tea is really sweet. The boba is always cooked perfectly -- never too chewy or too tough.
The staff/owner here sincerely try to ensure that your drink is prepared according to your preferences. They always ask if you would like to customize the sweetness of your drink and are happy to share their honest opinions about some of the beverages. After serving your beverage, they encourage you to let them know if any adjustments need to be made.
The service here is truly top-notch and is what keeps me coming back. The owner is a really nice guy and will remember you on repeat visits.