I think it changes every year but I've used them all over the years. Anecdotaly, I reckon D,A,C, Pablo Honey, B in that order.
D is the most organised and fluid, A is also good (depending on arrival time). B & C seem to alternate in awfulness from one year to the next. C seems a longer queue but is better organised (more stewards) and moves quicker than B because a lot of peeps in C queue are from the campervan field and aren't lugging all their stuff in so get processed a lot quicker.
Last year I arrived at 2am, 4hrs after my mates, who were already in the Gate B queue, got put in a car park closer to Gate C so went there, and waltzed in an hour before them when the gates opened Wednesday morning.