The Church is one of the most unique and beautiful bars in the city. On the main floor there’s a magnificent island bar that almost spans the length of the church, complete with booths, tables and bar stools and a small stage that plays live traditional Irish music from 7pm – 9pm on Sunday – Wednesday.
Tour the Guinness Storehouse Factory and while you are out that way, visit the Kilmainham Gaol (jail) which is linked to a lot of the Irish fight for independence, and is where they filmed In the Name of the Father with Daniel-Day Lewis. You might need to book ahead.
The Dublin Passincludes the Guiness Storehouse, the Jeannie Johnston Tallship (highly recommend), the Glasnevin Cemetery, and multiple castles and museums
Also tour the Old Jameson Distillery.
Go to O’Neill’s Pub for some well priced, all you can eat, traditional Irish food. It’s a bit touristy, but if what you want is a hearty Irish meal in the city, it’s hard to beat. You can get a full Irish breakfast there as well.
My favourite restaurant in Dublin is The Pig’s Ear. It’s near Trinity College. I had the best cod I’ve ever eaten at that restaurant. When I got home I started teaching myself how to replicate the fish.
The Queen of Tarts bakery/cafe is well worth a visit. They make a lovely breakfast. Really friendly staff.

The National Gallery and National Museum, especially the Collins Barracks branch.
I really like the Winding Stair restaurant beside the Ha’penny Bridge for lunch or the pre-theatre menu.

Matt the threshers fish restaurant is great for dinner. Cocktails in the Shelbourne Hotel.
Epic the famine Museum is very interesting. Guinness Storehouse, National Gallery, stroll around Grafton Street and Stephens Green, have an Irish coffee on Dawson Street somewhere.

The Chester B library is lovely, with a nice cafe.

We tended to stick to chain restaurants, because the independents seemed eye-wateringly expensive.

Be prepared for beer/drinks to be £££ too.

The best thing we did was to get the train up the coast for fish and chips, but have stupidly forgotten the name of the place we visited. It was nice, much nicer than Dublin itself, and only about half an hour on the train.

We spend a lot of time in Dublin and LOVE it there.
Here are some places we like to go to:

Avoca - go to the restaurant on the top floor for amazing breakfast / coffee & scones / lunch. The shop is lovely to browse through too.

Ely Wine Bar - great spot for late night wine and cheese board / nibbles

Fallon & Byrne - over 3 floors - fab wine bar in the basement - great for a glass of wine before dinner / theatre. Deli and upmarket food hall at ground level. Formal restaurant upstairs. All worth checking out.

Bewleys on Grafton St. Was a quintessential old Dublin coffee house, has been taken over and restored but the Harry Clarke Stained Glass windows are still there and are amazing. Have a white coffee and a sticky cherry bun! Cooked Irish breakast also good,

Farrier and Draper - bar - open late, cool spot - check out the Georgian Room if it's open (not reserved for a private function) great cocktails

Bunsen - fab inexpensive burger place for a quick, quality burger

L'Guelleton - french food in a nice venue

The Long Hall - traditional Victorian Bar
The Palace Bar - another traditional bar where the Irish Times journalists used to drink after submitting their copy.

There's loads of galleries - IMMA (museum of modern art - fantastic site )
The National Gallery, always worth a look
The Hugh Lane
The Douglas Hyde
The RHA

Also loads of museums - the National Museum, the natural history museum, the little museum of Dublin - award winning and worth a look if only to see the interior of a Georgian House

Trinity College - wander the beautiful campus and go to the Long Room Library - it is amazing

Christ Chuch if you like old churches

St Michans Church, you can visit the crypts to see mummies which inspired Bram Stoker to write Dracula
The writers museum

There are parks - Sty Stephen's Green in the heart of the city and the Phoenix Park.

I hope you enjoy your time there!