The rough way to describe the different eras is Gabriel (prog), Collins (pop), and No Collins (more pop). I'm a fan of the first one, because that's where we get albums like "Selling England...", "Foxtrot", and "The Lamb...", all of which are pretty awesome.
He's worth delving into. His scope was broad; he helped discover and wrote most of Sheryl Crow's first album, he engineered for Madonna and Michael Jackson, he produced and played on records for Keith Emerson, Spocks Beard and Brand X. He was one hell of a weird duck.