It depends on a number of factors including how reliable they are, the prices (applied to paid) and the features. You could say free hosting is better, but its limited and restrictive in terms of the fact you have to do things to get the hosting, hence the ideas of Post-2-Host and showing Adverts on your website to allow it to be free.
Paid hosting however is more reliable, has a lot more freedom (within their TOS), and other factors.