Kagome and Inuyasha. Definitely.
Guys, Kagome IS Kikyo's reincarnation. Inuyasha and Kikyo were born to be with each other, but then Naraku screwed that up and Kikyo died.
Remember that Kikyo is dead.
So Kagome is Kikyo's reincarnation, right? Therefore, she is also Kikyo. Therefore, she and Inuyasha are also soulmates.
Kikyo is dead. Once they defeated the Shikon no Tama, I suspect that Kikyo's dirt/earth resurrected form would have went back to what it was. She and Inuyasha could have never lived peacefully together, because she's well, dead. And Kagome was there.
Hurp de durp, hope this helped.