The best of the freebie sliders that I have tried by a long shot. Well organised, flexible, and looks great. You add each slide individually which sounds cumbersome, but is easily the best way of achieving the results you want. And actually, it took less time to set up than many of the other sliders on offer that are 'simpler' in design.
There is a pro version which I haven't tried but if it's better than this free one then it's well worth the 12pounds they're asking!