Out of Metroid Prime 1, Metroid Prime 2:Echos, and Metroid Prime 3: Corruption, whats your favorite. I know the graphics on Metroid Prime 3 were freakin awesome, but it didnt have the awesomeness of the other two games. It didnt have extra suits, and the beams overlapped eachother. I thought both were a stupid idea.

I liked Metroid Prime 2 the best because the ship was really cool and it was just like the others. It had all of the other suit upgrades, and it has the 3 unlockable guns. Plus the extra visors, and nothing is copied like in Metroid Prime 3 with the plasma beam, and the X-ray visor. It was also fun and hard and 1 of the 2 metroid games that I cant beat the last boss on Hard mode.

The first one was better than the other two. It was like a remake of Super Metroid with the escape from the space station, the different beams to choose from, and the lava/crashed ship areas. Also had the badass Phazon Suit (I love the color black). The infra-red and x-ray visors were an awesome touch.

Echoes' light world and dark world premise was too unoriginal. In the same token, the story was more formulated than its prequel. I don't like when you're given the whole itinerary ahead of time. It makes the plot too predictable and boring.

The upgrades weren't nearly as cool. So you can see some invisible platforms and sound waves with the visors. Who cares?

I liked how they shed light on the Galactic Federation in Corruption and tried to throw more characters and dialogue into the mix. The bonus credit system added a fair amount of replay value. But the beams lacked diversity (especially in combat). The ending wasn't sufficient, either. I know Metroid games never had elaborate conclusions, but this is (seemingly) the end of the Phazon saga. You'd think there'd be more to it than a planet blowing up and "Mission Complete."

Super Metroid.

Oh, just the Prime series? I'd go with Prime 1. I enjoyed the story and environments of Prime 1 better than the other two games.

Let's see:
Prime- pretty much a classic game in first-person shooter mode. Lot's of puzzles, addictive gameplay, and the game that started it all.Amazing graphics and music as well. You can also unlock the original Metroid and use the fusion suit in normal gameplay eventually.
Prime 2- The ultimate Nintendo cliches return, light and dark worlds and beams. Very extensive world though as the doppleganger is practically another whole world.
Prime 3- very good graphics and uses Wii controls to their fullest. It's still too short and you start over right when you clear game save. The way you unlock extras is kind of awkward as well.
In conclusion: first one is the best, then third, then second.