The Han helmet is a bit too small to fit over his huge noggin. Which is okay, since I already have 5 troops sitting on the shelf, and is his helmet fit I would be tempted to put it on him and sit him with the rest. But his arm would look really goofy if it wasn't holding that helmet.
As for the best GG bust done so far? I would have to say Boba Fett is the coolest one. Even though he is my favorite character, the pose and detail on him is just amazing.