For Airbrush I think Tamiya are my favorite.

They go on so nice with just a bit of their airbrush thinner and are easy to clean up

Second favorite is Vallejo Model Air. They have nice color sets geared towards certain subjects like modern navy or airforce etc...

The plus for me is that my local hobby lobby and game shop both carry Vallejo paints

For Painting with  brush, I also like the regular Vallejo as well as Privateer Press P3

easy to paint and hide the brush strokes

You can also thin them for the airbrush with the Vallejo thinner