The Blackwell series began in 2006, a collection of 5 proper good point and click games featuring a girl and a ghost solving paranomal-ish mysteries. The Blackwell Epiphany is the finale of them, and is actually the first Blackwell game I ever played.
Rosa Blackwell has a kind of love/hate relationship with her familial ability of mediuming. By The Blackwell Epiphany, she's pretty much accepted it, and her spirit guide Joey, an appropriately wise-cracking 1930s trenchcoated ghost. As a capper to an almost decade-long series, Epiphany is great, with stories resolved and emotions flying all over the place.
But it's also a great game in its own right, and playing it first is what made me want to go back and try the whole series. The writing is great, the puzzles are cool and challenging but not too obscure or weird - but most of all, the art is gorgeous. It's expressive and beautiful in that way that only very good pixel art is.
The Blackwell series as a whole is the work of Wadjet Eye games, what done Unavowed, another very good, paranormal point and click adventure. I'm not sure there's another studio doing 'em better, to be honest.