If you're looking for manga similar to Megazone 23, you might like these titles.
World War Three is over, but for nomad soldier Deunan Knute and her cyborg lover, Briareos, the greatest challenge lies ahead, not in the abandoned cities and DMZs of a post-war battlefield, but on the streets of a new "utopia." Shirow Masamune's visionary Appleseed is widely regarded not only as one of the linchpin works of graphic fiction, but one of the most influential science-fiction stories in recent memory, culminating in the astonishing 2005 animated adaptation. Appleseed Hypernotes, never before collected in America, features an over 80-plus-page Appleseedtale, plus reams of detailed information and art of the characters, machines, and weapons of Appleseed, presented in a non-Westernized, right-to-left reading format, as originally published in Japan.
Six tales of mecha war and redemption. Civil war has broken out on the planet Sodom, and the only way to survive is by using the mechas left behind by a mysterious alien race. The two sides must find common ground in their humanity or they will annihilate each other.