I'm interested in opinions as to which receiver would be the better purchase for the present as well as the future.
From my perspective the answer is obvious, the Onkyo hands down. It is simply the most powerful and flexible receiver in it's class. A couple of things to consider before buying it however. One, it is very large, and may not fit well in some audio cabinetry or other entertainment centers. Two, it needs plenty of breathing room as it runs very hot (just normal operation) and many people seem to have a lot of problems with that. I could care less, and if it ever seemed like it was a problem, I would just put a fan on it.
The build quality of the Onkyo is superior to the Denon as well, and it should being that it weighs 20 pounds more.