I was dissapointed to find out you had to pay to get into St. Patricks (5 €) and that the shop was larger than the cathedral itself. I didnt pay to get into a shop, instead, I enjoyed the outside of it.
Unique Suggestions: go check the garden besides it. It is incredible
Fun Alternatives: St. Mary's Pro Cathedral, small, off the typical routes, free and charming.
It’s somehow surprising to find that, inside St. Patrick’s Cathedral, there is more space devoted to the commerce of souvenirs, than to actual religious devotion. It didn’t bothered me, as I were focused in the architectural details of the Cathedral, but I guess some people could find this annoying.