Metroid Prime trilogy is easily my number one choice. Those games look better than most modern games in terms of art direction, and even technically in some ways. Imagining them in HD......I would be so happy.

Majora's Mask: Only 3D Zelda I have never played. I almost bought it, and then I heard rumors of a remake. Please make it happen Ninty.

None.
They should make new games instead.

is Nintendo. 

OP: Metroid Prime Trilogy HD; Xenoblade HD; Starcraft 64 

Why can't they do both?  Its not like HD Collections require huge production teams.  At Square Enix it took 2 people to make Kingdom Hearts 1.5 HD Remix and they lost the data from the first game and had to redo everything.

I am not sure what you mean by "regular discs" in reference to Wii U. 25 gig discs are more than enough room for multiple HD games.
I am mainly a PC gamer so these HD collections have no appeal to me. I never lose the ability to play me games any more. It was once an issue but now that I use Steam for everything I never have to worry.
I got a Wii U this gen because I wanted something different and both 360 and PS3 seemed too close to Pc as far as library goes. I really hope they focus more on new games rather than remaking them. I know many people saw the pulling of BC from PS3 and HD re-releases coming out was a good thing but I never liked the idea.

Nintendo's current difficulties with providing an adequate stream of games suggests they need every last bit of manpower and resources they have on the new games front.

So many games I'd like remastered in HD (F-Zero GX, Eternal Darkness, Punch Out Wii, etc) but I'll keep it strictly "collection" worthy.

In this order:

1. Metroid Prime Trilogy HD

2. Zelda HD Collection (Ocarina, Majora's Mask, Twilight Princess, Skyward Sword)

3. Super Mario HD Collection (64, Sunshine, Galaxy 1 & 2)

4. Rogue Squadron HD Collection (trilogy)

5. Smash Bros HD Collection (trilogy)

6. Mario Kart HD Collection (64, DD, Wii)

Your seriously saying they can't take 2 people to make an HD Collection?  And its not like a HD Collection takes years to make, they would get it done pretty quick.  They don't even have to take any manpower away, just hire 2 extra developers to make a HD Collection then let them go after if they wanted.  Hell they might even be able to do it with 1 person, with KH they lost the data and had to start over, I bet Nintendo still has all that shit still saved.

Wow I just looked it up and your right, I had no idea Wii U discs could hold that much memory.  I just assumed since they weren't blu ray that they were regular dvds.

I think those two people could be better employed elsewhere. HD doesn't add enough to a game for it to be worth doing in my view.