I've been to Finnegan's Wake, it's nice and the beer is good.

The Mudlounge on East Walnut is good too, though due to popularity it can get crowded and hard to find a place to sit on a Friday and Saturday night.

I also like Linburgs up at Commercial and Campbell but they don't have Guinness on tap, only drawback to that place. The other thing to warn ahead of time is they have a cover charge on nights when a band is playing.