I've tried the foam, the regular liquid, and dr. lee's liquid (#500).
Regular liquid caused dandruff and didn't dry readily, so it left a greasy residue.
Dr. Lee's caused less dandruff and leaves very little residue unless applied too generously - then it leaves a white powdery residue.
Foam caused no dandruff and dries like light hair gel, not powdery or greasy. So in this respect it is best. However, it has a strong fragrance that I found annoying, so I've been using Dr. Lee's.