Galway - I dont have a clue.
Dublin - I just left this for someone else. http://chowhound.chow.com/topics/704278?tag=main_body;topic-704278
Other things worth a mention are:
Thorntons* for the 25e Lunch is very good value.
Chapter One* is worth a visit Lunch and Pre Theatre 40e or A la Carte 70ish
If you wanna splash out Guildbauds** is a pleasant experience, Lunch is about 50 a head dinner sky rockets.