Depends if you're shooting or sipping...
If taking shots at a party or bar, then low-end Patron Silver, 1800, or even Cuervo are fine. Ain't gonna much matter after the first one, with a pitcher or three of beer around the pool table.
If sipping and enjoying like you would a good Cognac, then I like something with more flavor, like Patron Reposado, Anejo, or Extra Anejo that's been aged in oak for at least a short period of time. The longer the better. Increasingly pricey, but increasingly smoother and deeper flavor.
To that end, as with other fine distilled beverages, the sky's the limit if you truly enjoy it and have money to burn. Here's an example of a high-end Extra Anejo tequila:
Chaquira Beaded Jaquar Extra Anejo - Old Town Tequila
But, alas, tequila and I have had to part company.
While I enjoy it, we don't always see eye to eye.