O'Sullivan's (next door to Moulin Rouge, in the function room at the back of the bar) has salsa On2 (Puerto Rican/New York style) on a Sunday. The beginner's class starts at 6pm and the intermediate class starts at 7pm. There is a cha cha shine class for about 20 minutes at 8pm too.
Then the DJ starts until well after midnight (mainly salsa, a little bachata a little cha cha).
The cost is 10 Euros for the whole evening and includes one drink.
For any beginners out there that have been going to La Pachanga or Agua, note that this is on a different beat than you have been learning. For any intermediates, if this is your first time On2, I suggest you do the beginner class to get the beat into your head before you do the intermediate class. Of course, you can just come along at 8.30pm and dance whatever style you like!
This is a nice group of people and usually a small beginner class and reasonable intermediate class (not too crowded). There's always plenty of room to dance.