Great thread.
I miss more ports of real-time strategy games or just some great new ones. . This is one of those genres that actually works BEST on a touch-based interface. Starcraft, Warcraft, Age of Empires, a proper Red Alert... Bring it on!!!
iPad versions of Myst and Riven of course (what are they waiting for??). And Myst III and IV too!
I'm still looking for that really great platformer. LittleBigPlanet could work really well on the iPad I think.
Also I miss ports of those great Sierra games; Leisure Suit Larry, Space Quest, Police Quest... but I heard those were in the works! I'd pay good money for a Sierra App with a bunch of great old games.
GTA: Vice City and San Andreas would be great, and we already know the iPad can handle the graphics. I do think Rockstar will release this in time.