If you are in Dublin, Ireland, give all the Indian restaurants a miss! :) They cater to the Irish taste and I am yet to find a place where I am happy with all the three courses! And they are too damn expensive anyway!
I like Da Pino (Italian) in city centre. The pizzas and pastas are good and the portions are huge.
Siam Thai (Thai, as the name suggests) is good too and so is Mao (Asian). The Nasi goreng there is nice :)