Humbrol enamels mostly, because I grew up on the stuff, so to speak, but I do have a sizeable 'collection' of acrylics from various manufacturers which i use for 'fast turnaround required' sub-assemblies, bases,... (Tamiya, Humbrol, Valejo, Precision Paints,..). A handful of enamels from Revell too, purchased when I can not dfind the Humbrol equivalents...
I also use automotive acrylics in cans (primers and for airliners), oils in tubes (washes, drybrushing, stains, figures), acrylics in tubes (give colour to my plaster of paris), watercolours in tubes (washes).