pikmin 3 for me, I haven't play 1 and 2.

I'm surprised to see any other people who prefer 2 over 1. Most people think that a) the lack of overall time limit on 2 made it less strategic and b) the purples made it too easy. Well I say that a) the time limit in Pikmin 1 was NEVER EVEN CLOSE to being an issue even the first time through, and b) you still have to play carefully and there are still a lot of difficult hazards and monsters. Also, b-2) if it's that much of a problem just don't bring along any purples.

To me 2 beats both of the others on the sheer amount of content. Each playthrough takes me about 24 hours. And since I just love the very core of the gameplay, the longer I'm playing it the happier I am. I don't care if it's repetitive or less strategic or too easy or whatever. All I know is that every time I boot up Pikmin 2 I've got craploads to play through, and that's awesome. When I boot up 1, I beat it in one or two sittings. Also, tons of powerups that drastically change how you play, a huge interactive creature gallery with hilarious quips from Louie, about a million bosses, and tons and tons of fun and often nostalgic treasures to collect.

2 hands down. 1 lacks the content and 3 lies somewhere between. (And major points taken from 3 because of the completely pointless removal of c-stick controlling, which was literally one of the most important and constantly used controls in the series.)

Only played 2 and 3, like 3 way more.

Pikmin 1 was perfection. Pikmin 2 was the biggest let down ever! I'm only a third way into Pikmin 3 so can't comment on that.

Care to elaborate?

So much about what I loved about the first game was removed. The first was simple perfection. It's been so long since I played either but from memory - I hated the underground sections so much. Getting down 7 floors and then realizing I didn't have enough white pikmins or someshit... so frustrating!! Also controlling 2 main characters rather than just Olimar was very frustrating and made everything more chaotic than it should have been. It didn't improve the puzzles in slightest it just made the beautiful simple design of Pikmin 1 just chaotic and complicated. However, in Pikmin 3 it seems like they are using the 3 main characters well so far. 

After playing all 3 my favorite is still Pikmin 2, mainly because the underground sections remove the stressful time limits and allows me to relax and focus on not letting my pikmin get murdered.

 Pikmin 3. The level design is great ( it encourages exploration a lot), the bosses are fun, the graphics are colorful....

Pikmin 2 closely followed by Pikmin 3

Pikmin 2 was near perfection. Pikmin 1 started something amazing and had some strengths not seen in 2, like a real sense of importance to everything you found. Pikmin 3 looked pretty, but controls were shit. The first in the series I couldn't finish. I'll try to finish it eventually, but I found the controls so ineffective I just lost interest in the game. I'm a guy that likes to save EVERY Pikmin. Pikmin 3 makes this largely impossible due to not having the "order your whole army at once" command with the c-stick, or any sort of equivalent to it that I could find. I've never gotten so frustrated from a Pikmin game before. This game broke me. I was so pissed I stopped playing my Wii U for a looong time. It takes a LOT for a game to be so hard to control that I just give it up. Part of it is probably that I kicked so much ass at Pikmin 1 & 2, never losing Pikmin and completing in record times, that the shock of my usual strategies being made useless by an ineffective control scheme (both with the wiimote and gamepad) just disgusted me. Once I get around to playing it again, I'll probably figure out alternative strategies that will return me to my former level of mastery, and enjoy the game again. I was really disappointed that they took colors out though, seems like lazy game design or a rushed project. Or both. It also failed to really use the gamepad in meaningful ways, which was saddening, as it was THE game that made me want a Wii U, and I really wanted it to bring out some of the innovative potential of the gamepad.