It is a deep list. I have over a dozen but my top 5 must haves are:

1. Modern Warfar 2

2. Assassin's Creed 2

3. Forza 3

4. Splinter Cell Conviction

5. Halo 3 ODST

What's yours?

List of Some of the Games for the Rest of 2009:

6/9/09         8/25/09        9/1/09        10/13/09       11/10/09          

6/16/09       8/25/09         9/8/09        10/6/09        11/17/09    

6/23/09        9/22/09        9/22/09       10/12/09     11/17/09

7/7/09        9/1/09          9/22/09       10/20/09

8/4/09        9/1/09          10/1/09       10/27/09

8/14/09      9/1/09          10/5/09       11/3/09

in no particular order

Splinter Cell Conviction = OMG!!!
Modern Warfare 2
Halo: ODST
Assassins Creed 2
Forza 3

so....pretty much same as yours though like you said there is about 15 games on the way that I have to get this year.

Halo Odst
Forza 3
Splinter Cell conviction *my first*
Alan wake(if its an 09 release)
XBLA gem (Hopefully there will be a hidden gem)

Splinter Cell is all I want this year, so far.

Modern Warfare 2
Bioshock 2

And that may be it for 2009. Not sure what exactly is left and what platform I'm getting them on. These are guanranteed 360 for the rest of the year.

I rarely buy a game when it comes out... very, very, rarely. But I will consider buying ODST when it comes out and I will definitely purchase MvC2 on XBLA.

Halo 3: ODST, Shadow Complex, and Splinter Cell: Conviction are the only 360 exclusives I feel compelled to purchase. The game I am anticipating the most is Bioshock 2. 

I have high hopes for Risen and Brutal Legend. Hopefully some games surprise me.

1°- Bioshock 2
2º- Forza 3
3°- Splinter Cell Conviction
4°- Halo 3: ODST

@ Leo, Alan Wake is an early 2010 release.