I always use a flight search engine for my vacations. Not having a specific date or destination in mind, I chose the offer that appealed to me the most from among the inexpensive choices. So I chose a round trip Geneva - Madrid flight for €37 with Easyjet. I've found cheaper flights in the past, but still, for the time of year, that's still considered low-cost! ;-)
Our plane was on time for both the departure and return flight. The flight was pleasant, despite a slightly rough landing. Comfortable temperature, no in-flight information and friendly staff. The legroom was sufficient (I am 6'1").
For this price there's no onboard television, no magazines, you had to pay for any snacks, and only carry-on luggage was allowed. However, that's normal considering the price and we were fine with it.
In a nutshell: an inexpensive ticket and an on-time flight, which was exactly what I wanted. The expectations of a low-cost flight were met.