We Gotta Get Outa This Place -- probably the most popular among American troops.

M-I-C-K-E-Y -- very popular, because of the term "Mickey Mouse Shit."

House of the Rising Sun

Paint It Black

Ring of Fire

and a lot of others. I heard all of these and more between when I enlisted in 1963 and was discharged (honorably!!) in 1971.

Oh, and when you were in line the brass did NOT like you baaing like sheep.