They all fit differently at different ages and stages too. My general overview is
Tesco....fab fit, great value for money too (Erin is in their preemie nappies at the mo)
Asda....hated them, tried them with each child and really didn't like them. They leaked lots and I didn't like the whole design.
Pampers....baby dry are good but expensive
Huggies....2nd favourite, again they're expensive and I only buy them on offer
Aldi's....brilliant, much better than I expected. Only tried the size 3's, don't know what the other sizes are like.
Morrisons....ok, very similar to Huggies actually
Sainsbury's....disappointing and leaked