For a more technical and very much in-depth coverage of the topic of wanting versus liking check out some of Kent Berridge's review articles. I get the feeling that the majority of the linked to articles ideas have come from these.

http://www.lsa.umich.edu/psych/research&labs/berridge/research/affectiveneuroscience.html
http://www.lsa.umich.edu/psych/research&labs/berridge/publications/review%20publications.htm

The gist: how happy a wirehead is depends on the placement of the wires, of course. With appropriate stimulation of specific nuclei within the nucleus accumbens, ventral palladium and parabrachial nucleus you be quite happy without even wanting it. Dopamine is for dopes. Manipulating GABA system is where it is at.