I'll add my two pen'nerth:
Garrick near city hall not bad for bottled beer, nothing amazing but a decent selection.
Another decent food and beer place is La Boca, also near city hall. South American food and a few decent beers, run by the guy who started everything off in the John Hewitt beer-wise. Fairly close to your hotel I'd say.
Other than that it's the John Hewitt, Crown, Bittles, Kitchen.
A few other great pubs worth a visit, but not for the beer selection would be Morning Star, Whites and Kelly's Cellars.
Have fun, great city!