Tet Offensive (30 January – 28 March, 1968)
The “Tet Offensive” was a ‘great battle’ in the sense of its scale. On January 30th, the VC attacked roughly 100 Southern Vietnamese US held strongholds. This attack was swift and done in union (Yes, not unison). The attack was named “Tet” after the start of the Vietnamese new year (Tết). With the cost of massive casualties, the US was able to regain the majority of the territory lost to the VC (including Saigon). (https://www.historyhit.com/major-battles-of-the-vietnam-war/)
Hamburger Hill (10 May – 20 May 1969)
“Hamburger Hill” received its title weeks after the battle was over. Apparently, in the 1960s hamburgers took a long time to make, and this battle was no different (lasting 10 days). The battle took place on Hill #937 (named for its elevation above sea level). There were heavy casualties on both sides, though the US Military had more casualties than the VC by May 20th. The hill was abandon on June 7th because it held no strategic or military value. (https://www.historyhit.com/major-battles-of-the-vietnam-war/)