MG 1:100 MS-06S Char's Zaku II Crystal Ver
This was one of the earliest limited edition Master Grade Gundam model kits released by Bandai. Although the parts are cast from the same mold as the standard MG MS-06S kit, the plastic resin used is see-thru and colored (thus the 'Crystal Version' moniker) for the most part. Thus you actually do not want to paint the completed model, as it looks great unpainted due to the colored clear plastic parts. The kit is also great for kitbashing to create a hybrid MG Zaku using parts from both the standard and Crystal versions.
The Zaku II comes with a ton of weapons and accessories, and feature numerous opening panels to show off the interior mechanical details. Kit also comes with a bonus booklet titled "How To Crystal Version" which contains numerous creative ideas.