I'm going to say what I've said before...
Get a Blu-ray player.
The WORST Blu-rays you get will be better than the same DVD played on the BEST player on the market.
More importantly: All Blu-ray players in production will upconvert your DVD collection without issue, and you can enjoy them as well as your Blu-ray Discs.
If you love audio, then for goodness sake, you are passing up HD audio by not going with Blu-ray.
The price point of entry level - or even decent Blu-ray players is floating down to the price of the nice Oppo players and really is starting to make a lot more sense. As far as I can tell, unless you have a more specific reason to spend the purchase price of a Blu-ray player, on a simple DVD player, then you are making a mistake.
Especially as more concert discs are released on Blu-ray. Even if you aren't buying, the mere ability to rent and hear HD audio should be worth it for many music lovers. If SACD and DVD-A weren't dead before, the HD audio provided by BD will usher them the rest of the way out the door.
Yet, the Oppo is definitely one of the ways I would recommend if you are dead set against HD video for your HD display and just want to upconvert DVD.