Dr Faust is pretty great I think. I don't do as many layers as he does (...and my finished paint jobs aren't nearly as good), but for general techniques I think his style is about as advanced as I want to get - it looks great, without going to "Painting Buddha" levels of work.
Duncan from GW is also excellent as far as showing fairly simple techniques that don't take a ton of layers and still end up looking great. I use very few citadel paints, but it's fairly simply to substitute in colour from other brands.