I personally love the Ocho brand, but it's a personal preference.
Not only does it have a unique flavor profile that makes for interesting sipping, but it also has the feeling of something more expensive and memorable when compared to other tequilas on the market.
In my opinion, the best tequila is subjective to each person and what they like in their liquor - for instance, some people might prefer strong distilled liquor without much flavor while others prefer a more flavorful tequila with hints of fruit. Below are a few other brands that I enjoy (in no particular order) that you may want to try if you're interested in variety - Patrón, Avocado Reposado, Espolòn Reposado as well as this delicious recipe for margaritas on the rocks.