Dyson
We have the Dyson DC25 All Floors (with the ball mechanism). Bought it a few years ago as a Today's Special on HSN.
These machines are expensive, but hands down our Dyson is one of the best purchases we have made. It's right up there with the VitaMix in terms of my love for it and how often I use it.
Right after we got the Dyson we did a side-by-side comparison with our old (non-Dyson) vacuum. We vacuumed with the old machine (I think it was a Hoover), and then immediately with the Dyson. I was amazed at how much gunk the Dyson cleared off my supposedly "clean" floor. I was a believer from that point on. Plus the machine is lighter weight in comparison and, because of the ball mechanism, glides along the floor and swivels in pretty much any direction with a flick of my wrist.
We have about 40% hardwood, 60% carpet in our house. No pets, but a very very messy toddler.
Since you do have pets, you might consider the DC40, DC41, or DC50 (from the "Animals" line).
I've never tried out the Oreck so maybe there are Oreck lovers out there. I've just never felt the need to consider any other option since buying the Dyson because I love it so much.
Good luck, and sending wishes for clean and pet hair-free floors.