I have a three way tie for favorite, both with huge pluses & minuses...
Tamiya Acrylics
+++ easy to work with both airbrushing & straight brushing, easy to clean up...
--- very limited on colors, I don't like mixing my own FS colors
Model Master Acrylics
+++ huge variety of available colors, ready to AB right out of the bottle
--- don't always brush on that well & clean up is not as quick & easy as Tamiya or Gunze
Gunze Acrylics
+++ good variety of available colors, easy clean up
--- smell really bad, worse than enamels to my senses
Brian