I love both SE and Nintendo.  It's really hard to get a black and white out of it IMO, since at least for me, it depends on the games involved.  Between SSBB and FF7, I'd go with SE.  With Zelda vs. non-FF, I'd go with Nintendo.  So 0.5 and 0.5 split for me.

Seriously, I used to like JRPGS, and I used to like Square and Enix, then I realized that I'm doing more readingwatching movies than playing a game, and when it actually comes down to playing it's usually nothing but a menu where I select redundant options to defeat redundant enemies. Not to mention, for role-playing games, you generally don't play too much of a role at all, nope you just get to passively watch events unfold. Not that Nintendo doesn't make games I dislike, it's just they give me FAR more vareity in terms of gameplay than Sqenix, seems capable of doing, and their really good titles are some of the best in the biz. Heck I'd rate EA, Konami, Capcom, Namco, Ubi-soft, Bungie......can't think of any more, but the point is I have a very low opinion of Sqenix and all these companies as well as a glut of others rate MUCH higher in my book.

What kind of thing does them share

Nintendo Gamplay and pure Fun

Square Enix Super story but declined the last years

I gotta go whit Nintendo even though I love the old FF games more then many Nintendo games not all of them of course

S-E has managed to kill any franchise of theirs I enjoyed at some point (and no, I've never been a fan of FF games). Children of Mana is the only dissapointing game I've picked up for the DS so far (and sadly the reason I had purchased my DS on a whim).

Nintendo consistently puts out highly polished games. Square Enix is less reliable, some games are massive hits, others ginormous belly flops. Nintendo gets my vote.

Soriku, please,

Bleh, I'll never forgive Square for killing Final Fantasy. Although I still like DQ and KH, I'll go with Nintendo.

Square makes great games but they are nearly all the same genre. Square may win at the RPG field but Nintendo makes GoTY games in nearly every field. How can you beat Zelda/Metroid/Mario/MarioKart?

Nintendo

Nintendo (for the most part) makes better, and more varied games than Square enix. I vote Nintendo
...Though I was thinking yesterday night, that Nintendo and SE are the two best publishers- hopefully nintendo, disney, and SE can all work toghether and make the next KH game for Wii, with another spin-off for DS :)

Nintendo all the way