I'm in the minority that believes the original is the superior one. Besides the urgency set forth by the 30 day time limit, I just didn't like the white and purple Pikmin all that much. They added a needless layer of complication to the selection process. Yeah, purple Pikmin are the bomb-diggity, but when they count for 10 regular Pikmin, there's not much benefit to them. And the white ones were pretty much worthless except for the occasional puzzle or enemy character that could have just as easily been weak to electricity.
Don't get me wrong--I really enjoyed the second game. But the first one was magical. The #2 did everything bigger (and arguable better), but it didn't capture the same feelings.