I've lived in Vegas on and off for six years and I'm kicking myself for not going to this place sooner.
The Double Down Saloon is on the end of a small strip mall right next to the Thomas & Mack at Harmon and Spencer. There is some parking but if you arrive too late you might have to park a block or two away. This is an area known to locals as "the fruit loop" because of several nearby gay bars. The double down doesn't care who you are. All are welcome. It's just here to rock.
This place is a glorious dive. Dark, loud and the walls covered in stickers of all the small bands that have played here over the years. Any place that sells bottles of PBR is just fine by me. You won't find a huge selection of brew. Really only the stuff that matters. You can also get a concoction called "ass juice" or a bacon martini and for some reason Slim Jims are also an option. Maybe they're friends with the Macho Man.
The crowd is pretty young without a trendy douchebag in sight. At times it felt a little like a high school party with a more abundant supply of booze, but there are people from all ages who show up.
On the night I was there a band called Forth Yeer was playing and they ripped it up. In all a great way to spend a Friday night. No cover charge. No drama. No waiting in line hoping some doorman loser likes your shirt enough to let you in. Las Vegas needs more places like the famed Double Down. A slice of reality in a superficial town.