What exactly are you looking for in a game?
Are you looking for comedy but still with a great story (full of twists)? Then Phoenix Wright is a no-brainer.
If you're looking for noir, then Hotel Dusk is the way to go.
Professor Layton, while a very good game, is far too casual in comparison with the other two, imo.
And by casual I mean you're able to play it in 5-minute sessions if you like. It's basically 100+ puzzles (or riddles, or slide puzzles - it varies greatly) with a general story that goes around it. It's less immersive than Dusk & Wright.
Out of Hotel Dusk and Phoenix Wright, Wright is imo the better game. But that's comparing "awesome" with "Awesome!".
If you want me to scale it somewhat:
Best game ever! > Phoenix Wright >>>> Hotel Dusk >>>>>>>> Professor Layton >>>>>>>>>>>>>>>> Generic good game.
