As well as Dublin & Madrid, they also fly direct (ish) to: Nice, London (ish. Gatwick is a big London airport), Birmingham. etc.
However they do sometimes take the piss. Until recently you couldn't fly near Barcelona. Paris is still Paris (Beauvaus (sp?)). Rome, Brussles likewise.
I think they once advertised flights to Copehagen, the capital of Denmark, but the flight landed in Sweden!
Don't know why you are being downvoted - while they do fly to a lot of off airports they do fly from quite a few airports, we flow with Ryanair from Edinburgh to Marrakech earlier this year and it was perfectly OK. They were the only airline flying direct and as we were only going for 3 nights we didn't want a long detour via a hub.
Having said that, the Ryanair website is pure evil - the fact that the option to not buy insurance is half way down the list of countries is an example of just how devious they can be.
However they do sometimes take the piss. Until recently you couldn't fly near Barcelona. Paris is still Paris (Beauvaus (sp?)). Rome, Brussles likewise.
I think they once advertised flights to Copehagen, the capital of Denmark, but the flight landed in Sweden!