Honestly, though I picked Twilight Princess just because I love that game and it would be cool to see/play an HD, prettier version of that game, I'm going to have to amend the question asked.
Which Nintendo games period, would I like to see remade (if we're sticking to just strictly remakes), on Wii U?
I do this because there honestly aren't too many Wii games at all that I would want them to bother remaking, whereas there are several from older consoles that I'd LOVE to see, and I'll go ahead and list the ones I can think of:
Wave Race 64 HD: I'd rather have a totally brand NEW HD WR game, but if I can't get that, I'd love to get WR64 with that treatment. Honestly I wouldn't mind the GC WR get that treatment instead, as it basically was a faithful sequel, and I suppose it did have a bit more content.
Mario 64 HD: Yes, I know it was remade on DS, and that was okay for it's time. But when Mario Galaxy 2 came out, it just felt (to me) like such an unnecessary sequel, it felt like a "Lost Levels" edition of Galaxy. EXCEPT for the remake level from Mario 64, that was awesome, because that level, even just in SD Wii graphics, looked fantastic, and I couldn't help feeling how much BETTER it would have been if they had just released a remake with that look of Mario 64 INSTEAD of doing Galaxy 2. So, take that even further, I'd love that same treatment, but remake Mario 64 in HD on Wii U. It's be brilliant and would sell very well.
Metroid 2: This often forgotten entry in the series is BEGGING for a color remake, in a similar 16-bit style to Zero Mission, the remake of Metroid 1 on GBA. This entry in the series and the story it tells deserve a graphical (and content) update of similar quality, and while I'm sure it'd be a shoe-in for 3DS, I'd honestly rather see it on Wii U, and play it on a big TV screen.
Link's Awakening: Same. This brilliant game, my personal favorite Zelda game, while it got a "color" adaptation for GBC, that limited color palate left a lot to be desired. Again, getting a full on color remake treatment in 16-bit or better style graphics, would be amazing.
Star Tropics: If we're never going to get a third game, it would at least be cool to see a remake of the first classic. Again, in an updated sprite-based or hand-drawn graphical look. As an eShop release, I think these kinds of remakes would do really well.
Pikmin HD: I would honestly love to see both original games (WITH their full features intact) get a Pikmin 3 graphical style update. Would cost them a bit more to do than these retro updates I listed, but it would still be great to see, and if I had to choose only one, I guess I'd pick Pikmin 1.
Chibi Robo: Again, I'd love to see a new entry in the series for Wii U, an actual full blown game, not the little kind of camera-based game they recently released for 3DS. But, short of that, a remake of the GC original would be pretty cool.
There are others, but those are the ones, just from Nintendo, that I'd love to see.
