I have both 999 and Hotel Dusk and they're both really good games. Don't have Ghost Trick so no comment. 999 is a game I can't recommend enough, if you want a neat horror-esque styled story with plot twists, interesting character backgrounds and MacGyver styled puzzles, then 999 is the way to go. Hotel Dusk was one of my first point and click games and I really enjoyed it. It has a pretty interesting story about Kyle Hydes past that somehow is connected to the mysterious Hotel Dusk but it also leaves a cliffhanger at the end. That's where The Last Window, the sequel kicks off I guess. Need to get that one. Have fun with whatever you end up getting.