i went to Colaiste na Rosann in Anagaire in Donegal and its great. The thing i loved about it was that its in the villiage of anagaire and you can just walk to the shops and all the locals speak irish ad you really feel like you're in the gaeltacht. Also- the best thing ever- there was a chipper in the town (my Bean an Tí's cooking wasn't very good). They even spoke Gaeilge in the chipper!
The Colaiste is pretty good aswell-they brought us on loads of trips,which was cool beacuse friends of mine spent a lot of their time in other gaeltachts just playing football or volleyball all day. We used to go to the beach and go into Dungloe (nearest big town) and we went to Aranmore and climbed Mt Erigal.