I did the Guiness Storehouse one morning before work when I was working in Dublin, it would have been rude not to given I was working about 200 yards up the road. I quite enjoyed it, the smells were glorious and the pint of Guiness in the tower was very good. Great spot for minesweeping pints of Guiness as all the people who didn't like Guiness had one sip and left them. Must have had 4 pints before going in for the last day babysitting the staff I'd been training.
The best pint of Guiness I had was in McCanns Bar just opposite where I was working, it was the closest pub to the Storehouse gate iirc, that was a magnificent pint