If you can get to the 'Dise before there's nowhere to sit down, it's one of the most fabulous dive bars on the planet. If you can't find a seat, you might as well leave. I dare you to try to have a beer while standing there. It's quite the unpleasant experience.
My top 3 reasons for loving the 'Dise:
1) Slayer, old school Metallica, and Interpol on the jukebox.
2) Incredible fried cheese curds (here, they're called "cheese balls").
3) $1.25 longneck PBR's on Wednesdays.