I did major research for our trip last summer for our trip that included flights from London to Dublin, Dublin to Majorrca.. and then to Paris.
I have used Tuifly, Easyjet, Aer Lingus, Berliner Air, and Vueling .
Ryanair was best choice from London to Dublin, Cheapest and best flight times.
Out of all our flights the one on Ryanair was least eventful. We simply had no issues.
We bought tickets WELL in advance.. paid 40-50 GBPs as I recall. I also prepurchased one bag checked luggage.
Buy as soon as sure of dates. Pay for checked luggage ahead of time, and pack light .