Belfast or Dublin

My vote would be for Dublin simply because there is a lot more to see in the city if you are staying put. Belfast can really be seen in about a day. If you have three nights, and only two days then you can see the major sights of Dublin in two days from the hop on hop off bus, if you three days then you can do a day tour to Newgrange or some other place, also. From Belfast you can do a day trip up to Giant's Causeway and other places, but it will really come down to what you like. I actually spent for days in each place and managed to fill them with day trips and just wandering the city. Belfast is quite a bit smaller than Dublin, though, and I think downtown Dublin sights are much more walkable than Belfast.

Have not been to either yet but we are going this spring. From what I've researched, Dublin would get my vote. So much to see there & looks very walkable too plus someone said you could use bikes to get around too.

Agreed - Dublin. There's more to do there. However, I will say that Belfast resonated with me more because you can see the impact of "The Troubles" so vividly all around you.

I agree with Dublin too.
What I did was a day trip to The Giant's causeway with Wild Rover Tours. It stops in Belfast and you can either take the Titanic Museum tour or a Black Taxi tour. I did the taxi and felt more informed about Belfast.

Belfast and here's why.

Titanic Museum
Belfast City Hall
Crumlin Road Gaol
Black Cab tour of the Troubles
Mourne's Seafood
The Spaniard Pub
Lyric Theatre
Belfast Empire Music Hall
Ulster Museum
Botanic Gardens
St George's Market
Belfast Exposed Photography Exhibitions
The Giant's Causeway
Take a Belfast Hidden Tour http://www.belfasthiddentours.com
Try the Cuban Reuben at the Cuban Sandwich factory on Church Lane or at their stall in St George's market.

and take a train ride to explore Dublin and and return on the same day.

Paul Scales, I wouldn't say I was obsessed by the "Troubles" but I did find the exhibits and murals in Derry quite moving and inspiring. Seeing the progress that Northern Ireland has made in my lifetime gives me hope about what humans can do. Actually visiting one of the cities and spending a peaceful evening and day there reinforced that hope. It was a highlight of my trip last summer.

I was also able to enjoy many non-Troubles related sites and experiences. Northern Ireland definitely has much to offer besides that part of its history. I look forward to spending even more time there on a future trip.

If you only have time for one, Dublin is far more charming and historic than Belfast - it's a thousand years older. Dublin is very walkable, and many day trips in and out of town can be booked through Viator.com If you have time, do take the train up to Belfast for a day. It's easy, fun, and pretty.

If you only have time for one, Dublin is far more charming and historic than Belfast - it's a thousand years older. Dublin is very walkable, and many day trips in and out of town can be booked through Viator.com If you have time, do take the train up to Belfast for a day. It's easy, fun, and pretty. The train ride is pretty - not Belfast.