Casey Moore's is my personal first choice for a night out in Tempe. So many bars in the area have the typical rowdy college vibe, which is fine for some but not my thing. The atmosphere at Casey Moore's is relaxed and perfect if you want to have a good conversation with friends over drinks.
The food is tasty and comparably priced to other dive bars in the area - not cheap, but fair quality. Casey Moore's does include an appetizer discount during their happy hour which saves you a couple bucks. Honestly if you're coming just for drinks, an appetizer plate will do a fine job as an add-on since they're really entrees in my eyes.
Speaking of drinks, there are plenty of standards as well as microbrews on tap. The service on refills is speedy too. As a bonus, if you're like me and can't have gluten (or if you're not a beer person), Casey Moore's offers Angry Orchard hard cider on tap.
Casey's is my favorite place. Definitely put it on your list if you'd like to avoid the typical Mill Avenue crowd.