ryanair doesn't fly into any major airports... and often doesn't fly into major cities (ie doesn't fly into Amsterdam at all).
like Domino said, just remember that there is an average 10quid airport tax on top of the fare...
pretty soon ryanair will be the equivalent of a flying bus... they're losing the reclining seats, the headrests, the seat pockets, the footrests and eventually all you'll be able to take on board is carry on luggage - no more checking in bags! all this is to keep prices down though, so all good.
alternatively, try easyjet: http://www.easyjet.com/