The mfn ones are pretty good, actually very good, Tony at vivdvapes does them. The banna cream and simple glazed ones are delicious.
But, i personally found yorkshire vapers jam and custard ones the best around. the flavouring they use for the donut itself is so good. it genuinely tastes like a sugary, deep fried thing. The jam as well is the best jam in an e liquid i've tried to date. It actually tastes like jam, it is sweet and strong, just like jam is irl.
Didn't get on with NomNomz Donut but the best one I've had is Dunfords Dugong donut. Amazing flavour and I've seen them advertise a 10% with POTV10 discount code. Hope it helps.
Also here http://www.customvapez.co.ukThe shop near me do a lovely toffee doughnut and other doughnut juices, its pretty damn good, like it much more than the nom nomz dough boy, didnt get on with that. Think you can order via their Facebook page, called custom vapez in chester le street. Its 70/30 and £10 for 30ml but he does 3 for £25, the rest of his line of juices are amazing, some of which are attached.