I've been coming to the Rum Runner for a few years now. Almost once a week. I used to come here several times a week, but apparently the word's getting out that this is the place to go for some reason. I wouldn't go that far, but it's still a really cool place to hangout if live on the South East side.
Typical experience: dark, smoky, lots of sports going on big screen TVs at all times, and hustlers playing pool. A lot of people who come to this bar are Wisconsin transplants or tourists (so hoping you're not from Minnesota) this is actually pretty welcoming.
Don't be surprised if a drunk falls into you. That's how they roll out there apparently. I've never seen a hobo in this bar (which is good for this area). I've seen them passed out on Tropicana around there, but at least 200 yards away from this establishment. The atmosphere can get really intense during Wisconsin college games to freaking nuts during Packers games - which makes it kind of cool. You can get a lot of great food from the built-in diner (The Badger Cafe).
Lots of Wisconsin fare - cheese curds, Johnsonville Brats, etc. are the norm. Which is pretty awesome and hard to find around these parts. You can also eat at the bar. I like to eat at the bar because you can get 25 oz PBR drafts for $3 anytime. Which can't be beat in Vegas. The staff is basically very friendly whenever I go there.
Sure, you'll run into a scumbag or two when hanging out at the bar, but (at least) that's why I like to go there. It's diverse.