Ryanair perhaps isn't there because believe it or not, they are actually more lenient on credit card fees than many other LCC's.
EasyJet, Jet2 and Ryanair all don't charge for Debit Cards. For Credit Cards, EasyJet and Jet2 charge 2.5% of the total booking price, Ryanair only charges 2%.
EasyJet and Ryanair both also allow you to select your payment method on the very first page. Therefore you can see how much your booking will cost with either a debit or credit card right from the very start, so you don't get that last additional cost spring up on the very last page.
So out of EZY, LS and FR... The truth is that Jet2 is probably the worst (because you aren't shown the price until the very end of the booking), then EasyJet as they allow you to see from the start and then maybe to some people's surprise, Ryanair is the best by also showing you from the start and charging 0.5% less.