Bandai's 1/100 Master Grade Sinanju was my first build of 2009*.
(I haven't proofed this article, so suck it)
From a build quality this kid if fucking fantastic. Not only does it look great, but it's a big sucker, considerably taller than most MG Gundams. Much to my surprise this kit lacks pollycap joints. While I hated that on my Crossbone the mechanics here are great. The joints are innovative and make for lots of movement. The only issue here is that the shield can be a bit heavy (at least with the beam saber things attached) than the arm can support. If it's clipped on the forearm it has a tendency to pop off all to easily or slowly cause the arm to dip down.
This was one of the most frustrating models I've worked on. Not so much on part of the actual design or build quality but due to my own inexperience.