He's clearly shown more human than he's given credit for, although I expect a majority of TNG fans do give him credit for it.
I watched Phantasms last night, and it appears often that Data is worried, pre-occupied, distracted, and during the scene after he has the dream where he cuts off Troi's shoulder-cake and Geordi asks him what his dream was about, he appeared almost scared that Geordi might judge him, or come to the wrong conclusion about what he dreamt.
I personally thought he does feel emotions regardless of whether they are on the level of humans or not, but he rationalises these feelings in a way for them to make sense to him.
I also read an interesting article the other day where it hypothesises that the internet will grow so large, that it will start resembling the synapses of the human brain, that regardless of what it is made of as long as the complexity is there it could become self-aware and develop emotions. I'd like to think that's what happened, or was happening in a way, to Data.