Descriptive word: Irish.
I've been to House of Guinness a number of times, and each was a different but great experience. Located in downtown Waukesha, HOG is, in my opinion, the nicest of the many bars to spend the whole night (though the newly opened Bernie's will give it a run for its money).
It's a relatively small space inside, and feels even more cramped with its heavy wood tables and chairs. However, I've been to Ireland and HOG makes a great attempt at being a simple Irish pub; nothing overly kitschy and more of an olden, warm feeling.
I've been there for St Patty's Day (THE place to spend it in Waukesha, but expect MASSIVE crowds), a bar crawl where they had live music and dancing, and even a whiskey tasting. Their selection of liquors is respectable, and they have around 10 tap beers. Prices are maybe on the expensive side for Waukesha, but cheap if you're coming from most cities.
It's a go-to stop if I'm heading out in Waukesha. No question.