Onkyo 605. It is the cheapest receiver that decodes all of the new formats and it has been rated highly by many professional reviewers. I have one, and I love it.
Without knowing your budget and exact needs, I would say that the 605 is the way to go. If money is not that much of an issue, then you might want to look into Denon.
If you need more than two HDMI inputs on your receiver than you might want to look at the Onkyo 805.
You will be happy with any of those choices.
I have a very good samsung lcd tv but am using a less then hi def audio system. I am looking to get a home theater system that will either support or decode DTS HD and Dolby True HD. Does anyone have advice on which to pick up?