blimey - where to start?!
everyone will have their own opinions on this but i'll just give you my two penneth and also something else i've read recently. at the end of the day it will depend on you, your child and the individual carer(s) - there are good and bad examples of nurseries and childminders.
I, personally and IME, would say that children are better off with a good childminder up to the age of 2 or 3 just because of ratio of adult to child. If you can find a childminder who only has 1 or 2 pre-schoolers in the day i would say this is great, obviously depending on the childminder.
It used to be thought that, at two years old, children were ready for a bit more socialising and so nurseries were better for them as they didn't need such individual care and attention at this age. However, Steve Biddulph's lastest book and his research over the past few years suggest that nurseries are better for the threes and over, no younger.
It also depends on whether your child has a full or part time place away from you/the family, as a mixture of both types of care might be ideal for some children but not for others who might find it disruptive. will try to find link to article SB wrote recently - there was a thread about it.