If you don't mind a second opinion, not to step on Adrynalyne's toes, but I always find variety to be a good thing:
1-Hands-down RESCO!!!!
2- I use SPB Shell and it runs like a top on Omnia, plus you can skin it pretty easily with Imache's app!!!
3- I use S2U2, and I find it very useful as well. It doesn't have the light senstitve feature Adrynalyne likes, but it has full-screen caller ID, finger-friendly volume control, SMS + email preview, coupled with S2P (Slide to Play) you can listen + control music while the device is locked....the list goes on, plus...it is EXTREMELY customizable!!!!
4- If you use shell you don't really need any Today plug-ins, but Shell does come with a good one, and PocketPlus is a good one with many features included.
5- I found this, as I mentioned in 4, if you use Shell you don't need to worry about them, and I would only try this before you install to much:
I managed to remove mine by deleting the registry key at:
HKLM\init\Launch99
Found here:
http://forum.xda-developers.com/show...=368836&page=2
For a Contact Manager: I use PocketCM, it works well on the Omnia, is customizable, and (like S2U2) constantly under development + fully supported.
As I mentioned, all of Adrynalyne's choices are good as well, but I figured I would offer other alternatives. If you need any more advice or sites for all of these, just drop a message and I am sure we can help you out!!!