I'm new to this series (where has it been all my life).

i wanna play the games in the correct timeline's order (the one without Other M, i heard it's garbage)

I've started with Zero mission since that's a remake of the original Metroid title.

anyone help me out?

Go in order! Here it's the order!
-Metroid Zero Mission
-Metroid 2
-Super Metroid
-Metroid Fusion
-Metroid Prime
-Metroid Prime 2
-Metroid Prime 3
And if you want you can try Metroid Other M! I heard the plot was bad but the gameplay was good enough!

Zero Mission / Metroid
Prime series
Metroid 2
Super Metroid
Metroid Fusion

Try and avoid Other M

    The gameplay was good enough if you never  played a  Metroid game before. Exploration is what defines Metroid. Other M lacked what defines Metroid.

Prime series takes place directly after Zero Mission / Metroid

yeah that's what i heard, i've been addicted to Zero mission lately, the exploration and the sense of unknown is a lot more immersive than i though it would be!

Zero Mission, Super Metroid, Metroid Fusion.

I'd say not to bother with the 3D ones or Metroid 2. All you need to know about Metroid 2 is at the beginning of Super Metroid.

Fusion is a bit linear as well.

Metroid 2 is gonna be kinda a let down after playing Zero Mission (not so much if you played the original Metroid).

Prime series doesn't really add much to the overall story (minus the ending of Prime 3 and involvement of the Galatic Federation in Prime 2 and 3).  

To really enjoy the story of the Prime series, SCAN EVERYTHING.

why? a friend of mine played his old copy of Prime the other day, he let me try it, and damn, that shit's amazing!

       Exactly. If you enjoyed all the exploration then you have no reason  whatsoever to play Other M. Just play the Prime games and Super Metroid.