You'll want to dine here so you can watch the Irish dancing (nightly at 9:PM), not for the food. The food was OK, just nothing to write home about. The Irish dancing was close to Riverdance/Lord of the Dance in quality. For a great view of the show, reserve a table for around 7:PM - 7:30, have your meal, then you'll be perfectly positioned for the show.
The Arlington Hotel and Restaurant boasts that it is the most "centrally located" in Dublin. This is true. It is right across from the O'Connell Bridge and within walking distance to Trinity College.
The restaurant and pub/bar is decorated in a medieval theme and the menu features steaks and chops, some seafood. For all the sheep there are in Ireland, there was not one lamb entree on the menu! Service was a little slow, perhaps because most of the staff seemed new and just off the boat from Holland, or Italy, but you'll find that throughout Ireland.