Madhouse Coffee is my favorite place to get passion tea! It's $4 for a large iced tea, but it's something I don't mind splurging on. The large is HUGE, so it definitely will last you a while. It is 100x tastier than Starbucks's passion tea, especially with a pump of mango sweetener!
Also, their coffee is pretty decent too. I would recommend the drip blend (Ethiopian). It's absolutely delicious! I would say Madhouse brews some of the best coffee in Vegas.
The service here is always good. The people who work here are really friendly and personable. Plus, whenever my dogs come with me in the drive thru, the people taking my order always give them treats!