It might seem obvious, and I'm sure you know it already, but the choice of pickup can have a big effect on the tone of an electric guitar sound (one of many factors, of course). The neck pickup tends to sound noticeably fuller and warmer; whereas the bridge pickup, by comparison, tends to be thinner and a little 'colder' (but also 'tighter'). I have 3 pickups on mine - if I'm playing a clean-ish tone then I often use neck/middle, but if I'm playing something very distorted and metally, I tend towards the bridge pickup for more tightness.
To use your milk analogy: neck pickup is full fat/cream and bridge is skimmed ;-)
So, to get a a richer sound like that, he may using more of the neck pickup. He is switching pickups and tweaking the tone control knobs quite frequently as he is playing, so it seems likely that is at least part of the answer.
Have you tried asking him through YouTube what gear he is using? Also, it might help if you post a sample of the sound you are getting, so we can hear the comparison.
(btw, that guy is really good - wish I could play like that! :-) )