Out of the all the 2D Metroid games which is your favorite? Mine has to be Super Metroid. Many areas to explore and lots of secrets to find. Runner up is Fusion, it was a great GBA game but too short.
Never finished Super Metroid. I probs enjoyed Zero Mission the most but I haven't finished that either. Fusion and the X parasites which heal/attack you give it a non-conventional twist which can be annoying I suppose.
Easily Metroid Fusion. I love the power-ups (Diffusion Beam ftw), and it was like the 2nd game I got on the GBA. So I have alot of memories with it. =P I think total... i've beaten it like 20 times, since I keep playing every once in a while. =P