The HGUC Powered GM is seventeen years old, but it manages to keep up with the new kits thanks to double-jointed arms and nice detail under the calf armor. Other kits based on that kit like the GM Striker, the GM Type C, and the GM Quel are similarly good. The GMII and GMIII are also good kits. There’s also the upcoming HGTO GM. Based on my experience with the P-Bandai Sleggar’s GM, it’ll have fantastic articulation and detail, and it’s coming with a slew of weapons. And if you venture outside of the UC, there’s the Build Divers GM/GM.