The Swaro 20-60x80mm "HD" is in my opinion the cream of the crop. You will pay through the nose for it though.
I personaly use the 20-60x65mm due to its lighter weight and better compactness. However 90% of what I use it for is backpack hunting and works phenomenally. In 07 I counted 8 out of 9 growth rings on a dall ram at just over 765 yards.
If I didnt have to backpack so much I would use the 80mm version for better light gathering and overall brightness in early morning and late evening.
You will never be dissapointed in ANY swaro product or their customer service.