Kidou Senshi Gundam Thunderbolt

How would you survive in a war when your country considers you to be disposable? The soldiers of the Living Dead Division and the wZero Unit face this situation every day. Their hardships might be different, but every battle is a dance between survival and sacrifice. Be ready for some good mecha battles! While both anime are part of popular franchises, these entries can be watched without knowing their related series.  

-Both are set in space, but not outside solar system -Both have great jazzy soundtrack -Both are stunningly animated 

Bolth are mecha anime where the cast are seen as mostly expendable soliders. Bolth emphatise comradery between the cast. Characters, animation and ost is great in bolth. Thunderbolt requires little context from other gundam anime making it a great geatway into the franchise. 

Both anime... ...have stupendous animation, taking its time to show how the mobile suits work and how are destroyed. Also modernizing the designs of the original series. ...are short spin-offs of the one year war, in the universal century, depicting a minor front of the larger war, that is notable for the difference in scenario and equipment deployed. ...take a more realistic and gritty aproach to Mobile Suit combat, with emphasis in equipment, tactics and strategy. ...follow characters, and dynamics among them, in both sides of the conflict portraying in a relatable and human way. ...have romantic subplots, albeit managed in different ways. ...have people who are devastated by the consequences and destruction of war, and people who enjoy the fight and think only about winning. ...have nice people in Zeon.  read more 

* Both are short series that are spinoffs of a larger narrative from iconic mecha series. * Both feature top-shelf art and animation for their respective eras. * Both feature excellent soundtracks composed by former members of The Seatbelts. 

Both are incredibly dark shorter Gundam series taking place during other shows in their respective timelines. Both are fun, easily rewatchable rides, with MS design ranging from solid, to great. Both have very memorable characters and moments, and serve to further flesh out the conflicts of each series 

MSG Thunderbolt is basically LoGH in miniature: -Political confrontation in space between two human factions -Main leads are somewhat similar in personalities, especially with Reinhard and Io Fleming -Lots of fights in space with battleships/mechas.