Metroid Fusion on the GBA. It was given to me about 5 years ago, I had only played about an hour and dropped it until recently, I'm not kidding, it was boring. But recently I dug it out and started playing again And finished it in a couple days. I don't know what changed but I really liked it, and I had never played another Metroid game before, the backtracking and the fact that most health upgrades are hidden as if they were secrets had always put me off. I'll play through it again because I don't remember the beginning of the story much. After that I'll see if I can find a cheap copy of Metroid Zero Mission online.