We love our Whirlpool Duet Sport, and got it for a great price on sale at Sears (I think about $550). The very same model was at Costco for about $700 at the time. I wouldn't pay much more than that, because it doesn't make sense (to me) to spend an extra thousand dollars in order to save $50 or whatever a year in water. It would take 20 years to realize the "savings".
It holds a queen comforter, or the equivalent of at least 2 loads of laundry (compared to our old 'super capacity' top loading washers). Some do hold more, but I often find that I don't even fill it when I need to do a load. If you have a king-sized bed, that might be reason enough to get a bigger one.
When ours is on high spin, if there is stuff on top of it, it shakes so much that the stuff will fall off, which is annoying. So I usually put it on medium spin. I really love that it gets so much water out of the laundry - it takes much less time to dry the laundry, so that's an extra savings in energy. I think all front loading washers do that, though. Another bonus is that you use much less detergent (and water). One thing I do miss about a top loading washer is being able to dye things in it, but that was maybe once a year, so not a big deal.
If you don't subscribe to Consumer Reports, I highly recommend it. It rates washers and dryers (and everything else). The best deal is probably to get an online subscription (less than $20), then you can look up anything and not have to have the magazines around the house. They almost always recommend NOT buying extended warranties, as they are usually a waste of money and don't cover any more than the included warranty would cover (except for laptops, they said, so my DH got one for his laptop, and ended up having to use it, but pretty much nothing else).