I think one of the most important factors to look for in a loudspeaker is sensitivity...for a number of reasons. You can get excellent dynamics, obviously being the one most people think of...but more importantly for many consumers, you can pair a sensitive loudspeaker up with nearly any amplifier. With the way electronics, surround sound formats, connections, and all of that change...it's important to keep up to date without spending a lot of money while also getting excellent sound quality. The Pioneer 900 and 1000 level receivers have excellent sound quality as tested by Dr. Earl Geddes (the crossover distortion which he measures with his own methods is extremely low) and they cost less than $500 (less than $400 for the 900 level models). With the savings on electronics, it allows someone the ability to buy better speakers which will last quite a bit longer, especially if chosen wisely from the beginning.
In the $2000 range, I recommend GR-Research kit speakers built out by one of the available sources (N3X model), Salk Songtowers as mentioned previously...and I'd also check into some bookshelves. You'll always get better sound quality using multiple subwoofers...not even expensive subs, just have 3 or 4 of them. They will have smoother in-room response and free up the mains to handle the range they can do better. The Gedlee Nathans are just over $2,000, but I doubt there are many speakers that can hang with them. The resolution, frequency response, low compression, controlled directivity, and high sensitivity make for a great loudspeaker. There's also an interesting monitor I found at Selah Audio for around $2000 that uses a wonderful 7" driver with a tremendous RAAL tweeter...it won't be the most dynamic loudspeaker with the highest SPL, but in smaller rooms, should be quite enjoyable.