I won't bash you Jenny but here are a few things that could have been of interest:
Croke Park museum to learn more about our unique sports hurling and gaelic football. You could even take in a match.
We too have a botanic gardens. Probably a relic from your British ancestors. Nearby is the glasnevin cemetery as another poster said. A number of famous dubs and political figures are buried here.
Sure our museums are not as big as yours but sure yours don't inform ye of Irish history or culture. Try the free National History museum, the free natural history museum (the dead Zoo) both within walking distance of each other. Collins barracks. Kilmainham Gaol. Trinity College and the science gallery located in Trinity college. St Patrick's Cathedral. Dublin Castle (OK not as amazing as Edinburgh Castle etc but sure hey was built by your British ancestors).
Perhaps art is your thing. We have the National Art gallery (very near Trinity College, and not far from the National Museum and Dead Zoo). Plus on Sundays its worth walking around Merrion Square or Stephens Green looking at the paintings people are selling and speaking to the artists. Perhaps Asian art is your thing if so there is the Chester Beatty library. For modern art IMMA. IMMA has lovely grounds and often holds gigs.
There are also quirky places like smallest museum in Dublin (Georgian House in period style). The leprechaun museum (not my cup of tea). Our own wee wax museum (again no madame tussauds but if was people are your thing it's not too bad). You could paddle in the canals at the weekend for 10 euro or maybe rent a barge.
We have a number of Georgian squares and little parks. Stoney batter was voted one of the hippest places to live in Europe recently. You can check out some lovely neighbourhoods like Ranelagh, Rathmines etc
As for food we have loads of choice. The quality is fantastic too. You must do your research but there are plenty of decent places to eat that won't bankrupt you.
There are loads of good bars and pubs another poster has mentioned some good ones. I would include the Brazen head for tourists as it is Dublins oldest pub.
Yeah we have homeless people and drug addicts but we have been worse hit by the global recession than many other EU countries (not including Greece, Portugal and Spain). Yes we have thieves so does Edinburgh, London, Amsterdam, Paris etc etc (I've personally been robbed or seen someone robbed in these cities). Don't want to alarm you but Dubliners have sex too so if it bothers you better avoid the place.
Yes we are more expensive than other cities but as others have said we are a working city.
Come visit and see for yourselves. Most Irish are friendly but sure like yourselves we have our moments. Oh and I didn't have to mention Guinness or Temple bar in my short guide.