I can definitely reccommend The Arlington Hotel, it is situated right on the River Liffey, on O'Connell Street near Halfpenny Bridge. Very centrally placed (opposite Temple Bar area). Great atmosphere, friendly staff & great food. They have their own website: http://www.arlington.ie/ Click on special offers. They offer live entertainment every night too.
I totally agree with Kjohn. Whenever Im in Dublin for more than a day I choose to stay at The Arlington O Connell Bridge hotel (dont confuse it with the temple bar Arlington) and it is excellently located. Ever evening they have traditional irish dancing at the bar downstairs, which gets packed. Its a reasonable 3* hotel, nothing too fancy.
we stayed at temple bar hotel,right in the centre and was reasonably priced with breakfast,had a bar with sports on,and was lovely and clean,it was about 3 years ago but it wasn't expensive then!av a guiness for me!haha!