The biggest exclusives for each console, all planned for release in 2015. 

Which will be rated the highest and lowest on metacritic, and which will sell the most and least? 

I think ZeldaU will have the highest ratings and Halo 5 will have the lowest, but will sell the most.

Zelda will have the best reviews, as it's a Nintendo game. Halo will be lowest rated, but still with good reviews (85).
Highest selling will be Uncharted, then Halo and Zelda third.

Zelda U of course.

Zelda will sell the most too? 

MC

1. Halo

2. Zelda

3. Uncharted

Sales

1.Halo

2.Uncharted

3.Zelda

Halo and Uncharted sales should be close but I believe Halo will edge it out, also I have faith that 343i will deliver a solid Halo game making the franchise return to 90+ MC. I think the metas for all three of these games will be extremely close. Zelda no doubt will be high cuz it's a Nintendo game... if I didn't have faith in 343i I'd definitely say Zelda would score the highest.

ratings: Zelda > Uncharted > Halo
sales: pffooott. no idea. depends a lot on how the user base for XB1 and Wii U evolve in 2015.

What?

Will have best MC!

But which will sell the most? I asked that question too.  

Ratings wise:
1. Zelda U
2. Uncharted 4
3. Halo 5

Sales wise:
1. Uncharted 4
2. Halo 5
3. Zelda U

My most anticipated game:
1. Uncharted 4
2. Zelda U
3. Halo 5