I thought that this might be a good topic for stimulating a discussion.
Try to keep your answers realistic. For example, while a Master/Perfect Grade Devil Gundam would be awesome, it would simply be too much plastic for Bandai; a very large High Grade, like the GP03, Dendrobium would be the best you could hope for for the example.
In no particular order, the Master Grade kits that I would most like to see are: 1) a Master Grade Gundam X, 2) a Master Grade V2 Gundam, 3) a Master Grade Crossbone X-2 (it's surprising that Bandai hasn't fine this one already, given that we have the X-1), 4) A Master Grade Saviour Gundam, and 5) a Master Grade Aegis Gundam.
The High Grades would be: 1) HGAC Taurus, 2) HGFC Rose Gundam, 3) HGUC Den'an Zon, 4) HGAW X Divider, and 5) HGUC Neue Ziel.
Perfect Grade ZZ Gundam and Nu Gundam would also be nice.
What kits would you like to see?