There's a small sign over the front door at Erin's that reads, "Be nice or leave." Everybody tends to follow that particular rule, gathering in well-mannered groups around the bar, by the dart machines, or out on the smoking patio. In fact, the only time you'll hear any shouting at this friendly North Phoenix joint is when patrons have to holler to be heard over the rock and Top 40 tunes blaring from the jukebox. If you can wade through the weekend throng in this crowded corridor of a club, you'll find a dance floor where brave booty-shakers start getting down early in the evening. Surprisingly, Sundays are the biggest night, when such drink specials as $1 you-call-its draw thirsty, thrifty, and affable patrons.