Mobile Suit Gundam: The 08th MS Team, Soukou Kihei Votoms Recommendations
VOTOMS and Gundam are huge Sunrise franchises, so it is bound to be some similarities. However, I think VOTOMS is most similar to the 08th MS Team, since both anime share the love for gritty and realistic action, making them prime examples of real robot anime. Also, both of them have an 'impossible love' relationship and both are partially inspired by the Vietnam war.
Both series offer a futuristic but very real and convincing depiction of warfare, featuring utilitarian designs and grounded combat with an emphasis on tactics, a rare thing to see in the mecha genre even among real robot series.