Fox micro swingers for me. Having used just about every other kind, from dough-bobbins, foil cylinders, washing-up bottle tops (which I still use for roach, bream and tench) monkey-climbers (still second favourite for carp) and bobbins, I've concluded that swingers can do it all, with none of the drawbacks.
Consider: they're resistant to being blown about; they can be set to vitually weightless so you can fish really slack lines, or very heavy by sliding the weight forward - so much so you get rod tip deflection against a tight line - and anywhere in between; they take isotopes for night fishing; they are adjustable for different line thicknesses, and they won't flip up and tangle round the alarm or rod on a fast run.
Bobbins seem to be the fashion at the moment - probably due to the Korda dvds, Thinking Tackle shows on Sky and the fact that one or two high-profile carpers use them. Muddy Waters bobbins are all the rage 'darn sarf' with the in-crowd; I can't see the point myself as most of these chaps fish really slack lines to avoid spooking already pressured carp, and the only way they can do it is by laying the bobbins on the ground. The 2 gram 'old skool' (how pathetic) version is supposed to be light enough not to drop and tension a slack line, but then it's invariably attached to six (or even nine) inches of chunky sink plug chain weighing ten times as much!
PS half a crown was equal to twelve and a half new pence.