Just for rail, I quite like trainline.com. It tries to hide the madness that is very poor national/private rail service and their ticketing regimes, but really there’s only so much you can do, so often I get two or more tickets for legs of travel, some of which change as I remain on the same train?!?
Just a quick follow up, I haven’t been able to find Railboard pricing in the UK that is more than 1p cheaper than Trainline, so I’ll probably stick with the latter, which also offers pan-European ticketing, which is fairly important to me.