Kalonos: "A style of platform game with role-playing game elements and inventory items, involving more exploration than a traditional linear platform game."
By that definition, Metroid is not a Metroidvania, since it lacks roleplaying game elements.
Something like...
"A style of platform game with
adventure game elements, involving more exploration than a traditional linear platform game"
...would probably make more sense.
And yes, laying down the definition is important if we're gonna suggest some games to the OP. What he is looking for are action-adventure games with platforming elements, not action-RPGs.
Yes, I realize that Symphony of the Night has some action-RPG elements, but that is not part of the Metroid formula. These type of games, including SotN, are first and foremost action-adventures.