As far as 2D games go Super Metroid is the best.
In 1987 a lone bounty hunter named ,Samus Aran, went to the planet Zebes to destroy Mother Brain and eliminate the Metroids on that planet. She succeeded (or so she thought) and the galaxy was safe once more. In 1992 Samus dawned her power suit for a second time to take out the queen Metroid and take them all out once and for all. After it was over the last of the Metroids hatched from an egg and mistook Samus for it's mother. Instead of killing it she took it with her. This is where Super Metroid picks up. Samus turns the last Metroid over to scientists on a space station for research. After Samus leaves she gets a distress signal from the station and goes to investigate. When she arrives everyone is dead and the Metroid is missing. Samus goes to the end of the ship to find that her old enemy Ridley is back and is attempting to take the final Metroid. Samus fights but Ridley makes his escape. The space station explodes and Samus follows Ridley back down to where it all started, Zebes.
Once every game system you get a game so great that it becomes immortal. This is what Super Metroid has become. It withstands the test of time and gives you a game that just keeps on giving and leaves your wanting more. The basic premise to Super Metroid is exploration. Your thrown into a world that your familiar with but has changed. You wonder around the map searching for new power ups for Samus that will allow you to reach new areas. You do this for the entire games going from areas flooded with plant life to places flooded with water, all the while gaining new abilities such as the space jump and screw attack. Super Metroid is very much like its counterparts. It's just as good and even better. The gameplay is repetitive on paper, but in execution it gives you one of the most rewarding and incredably fun experiences you'll have playing a video game.
Boss fights and plentiful with almost 10 in total and each one is just as memorable as the last. Each one is huge with their own special strengths and weaknesses and are challenging to boot. Every one will leave you breathless and on the edge of your seat.
Playing Super Metroid is almost like a religious experience. What most Hollywood movies go for in the thrills and surprises department Super Metroid delivers in loads. The ending will leave you shaken and may even possibly bring a tear to your eye.
You can get this game for $8 on the Virtual Console. That's more than a great deal. You shouldn't be hesitant on whether or not you should buy it, throw down the $8 and play one of the greatest games ever made. As far as 2D games go Super Metroid is the best.