Kate
Dan Richards (Quality Comics 1942-1950 / DC after 1984?)
Paul Kirk (but with no costume: Adventure Comics #58-72)
"Rick Nelson" (Adventure Comics #73, April 1942)
Golden Age Paul Kirk (with costume, Adventure Comics #74, May 1942)
Starker, "Manhunter 2070" (1st appearance in Showcase #91, June 1970)
1970s Paul Kirk (1st appeared in Detective Comics #437, Oct.-Nov. 1973)
Mark Shaw (first appearance: 1st Issue Special #5, August 1975)
Paul Kirk clone (pre-CoIE; first appeared Secret Society of Super Villains #1, May-June 1976)
Chase Lawler (post-Zero Hour version; first appeared Manhunter #0, October 1994)
Kirk DePaul (1st appeared in Power Company preview in JLA #61, February 2002)
Kate Spencer (first appearance: Manhunter #1, October 2004)
Tangent Manhunter (from Earth-9; 1st appearance in Tangent: Superman's Reign #1, May 2008)
Kate
Reading List (Super behind but reading them nonetheless):
DC: Currently figuring that out
Marvel: Read above
Image: Killadelphia, Nightmare Blog
Other: The Antagonist, Something is Killing the Children, Avatar: TLAB
Manga: My Hero Academia, MHA: Vigilanties, Soul Eater: the Perfect Edition, Berserk, Hunter X Hunter, Witch Hat Atelier, Kaiju No. 8