I have been to Kinlay House in Dublin on New Year's Eve a few years ago and I can only speak well of it. The hostel is pretty near the center and at the bus stop which takes you directly to Dublin Airport.
The thing that struck me about this place is that despite being the last day of the year, so full of people, the hostel was clean. The bathrooms were cleaned every hour I think and the rooms and corridors and common rooms were also very impeccable. In my opinion this is the most important thing when you decide to sleep in some structure, be it a hostel or a hotel.
The hostel is pretty great, on the ground floor in addition to the reception there is also the kitchen and a very large room with tables. Here I had dinner on the evening of December 30 making use of the kitchen and making myself a nice pasta dish together with friends. On the other floors a lot rooms with tv rooms and billiard room and rooms, double and dorms, mine was for 6 people.
The prices are quite low, I remember spending no more than 20 € for a 6-bed room New Year's Eve, so no more than other hostels and certainly a little less than some hotels. Obviously if you have any higher demands this is not the right place, but i must say that the location, cleanliness and cost make this hostel a more than great place for me for a few days in Dublin.