Not wanting to be seen to pick on EZY, let me volunteer my vote for the worst website. BMI without a doubt - your votes?
KLM's is pretty lousy but getting better, though still causes too many javascript errors. EZY's is one of the best I've used; I especially like the "boarding card on booking" feature rather than having to go back for it 24 hrs before, though this is probably only feasible for airlines (like EZY) that don't normally overbook.
The only problem I had with EZY was the awful punctuality of the 1545 AMS-LTN. This has now been resolved...by cancelling it permanently. Nice one, leaves me with KLM to/from LCY as the only real option. While it is my preferred option, it does crank the price up a bit...
