I have Gamestop game credit that I have to use and am looking to pick up a game and trade it in the following week.

I may not even play it.  Its a long story...so just go with it. :)

I need to know which of these games (in your opinion) will have highest trade in value 1 week after release.

1. Spider-Man: Shattered Dimensions

2. Tom Clancy's HAWX 2

3. R.U.S.E.

I'm leaning towards Spiderman, but I really don't know anything about RUSE or HAWX 2.

If I had to guess I would say R.U.S.E.  or Spiderman,  definitely not HAWX,  the first one wasnt very good.  The only game I have heard buzz for would be R.U.S.E. so if I had to choose it would be that one.  

Its a shame you couldnt hold off till Halo Reach.   Could you just preorder a copy of Halo: Reach with it and trade it in the next day?

Nah...I already have Reach preordered personally but I can't do it here.

Basically a buddy told me that Transformers is losing half of its trade in value after Friday. 40 to 20 bucks...

On top of that, they have a deal on those 3 select titles next week where you get 50% more of the trade value towards the new game. So 40 plus 20(50% of 40) = free new game.

So I am looking to get the game with highest trade in and then trade it next week for the next weeks 50% trade in offer...which is most likely Reach :)

If thats the case then I would say R.U.S.E. or the Spiderman game.  Leaning towards R.U.S.E. more.  

I would say R.U.S.E., spiderman will probably have more sales resulting in higher returns. Also, the type of consumers buying R.U.S.E. are more likely to keep the game than the one purchasing spiderman.

Ruse. I can see Spiderman : Shattered Dimensions going down to 39.99 - 49.99 in a couple of months.

RUSE.

Definately not Spiderman.