-Planescape: Torment
Not a sequel to the storyline, but a similar experience in a similar setting would be excellent in a modern generation.

-Grandia
Not the best series ever, but attach a good plot to it and you'd have one of the best RPG's ever.

-Dark Cloud
A great series that was unique and inventive. Shame it never got another sequel. Dark Cloud 2/Dark Chronicle was excellent.

-Wizardry
An excellent series. They had a Japanese company develop a spin-off for PSN, but it was trout. Get a better company to develop it and you could have another great series.

-Caesar
Great series, hope they make a new one.

-Chrono
One of the best RPG series ever.

-Might & Magic
Update it a bit regarding plot, but keep the awesome old-school magic and you'd got a winner right here.

-Baldur's Gate
Though it seems to be making a revival with the remakes and a possible BGIII if Enhanced Edition does well.

-Final Fantasy Tactics
I would like one more like the original, although FFTA and A2 are good, I like FFT's story more.

-Dance Dance Revolution/Karaoke Revolution
Let's be real. You love it.