The last couple times I went to the store and picked out random mystery games, I burned myself. I got a Sherlock Holmes game in which the camera gave me migraines, but that was actually the best thing I got. I got this DS game called Lux-Pain, which is awful. and I got a game called Cate West: The Vanishing Files, which ended up being a "Where's Waldo" kind of game, where you are given pictures and have to find like 20 hidden items. Terrible and misleading game.
I really love Phoenix Wright. I have all four PW games. I used to love the old Sierra and Lucasarts games, like King's Quest, Indiana Jones and the Fate of Atlantis, things like that. I got Zack & Wiki, and I loved that. Might be my second favorite Wii game.
There's a lot of crap mystery or crime games out there though.