Belfast was great - there was a free shuttle into town (drop off across from the city hall). We did a hop on hop off bus tour with live commentary (Belfast Sight Seeing Bus). The tour guide was terrific, the staff friendly and helpful. We also went to the pump house museum which is were the titanic was built. We paid 6 pounds for a tour which was very interesting and well worth it.
We bought a shuttle ticket from NCL for Dublin ($10 per person) as there was no free shuttle. They said it could take up to 45 minutes to get to the city center, it was more like 15 minutes. Anyways we did a hop on hop off bus tour - We didn't stop anywhere because there was nothing that overly interested us. We walked around Trinity college and went into some store. One thing we noted was that there was a lot of homeless people around. The weather wasn't great so we went back to the ship pretty early.
We did the Golden Circle Tour which everyone told us was a must - and it is! I felt as though we saw a lot that day. I wish it would have been an overnight port as I would have loved to do the Blue Lagoon tour as well.
We had rain when we were in Bergen, but a great port none the less. We did a city tour and the train car up floieng to the view point. It was a great tour. After the tour had ended we walked from the ship back to Bryygen which I would recommend. Spent some time in the shops.