Several have mentioned other types of studio monitors. They all have their benefits for mixing engineers, but the sound isn't always as nice as a set of audiophile speakers. Studio Monitors are usually designed for mixing engineers that have a very different requirement (need to pull out and identify individual instruments for a good mix). That doesn't always equal a pleasant sound (or as pleasant).
The Acoustic Energy AE1 are some very excellent active speakers, but they are basically four times as much as Audioengine 5+.
I think the good old Yamaha studio monitors sound very natural as well. The HS5 are at the same price point of Audioengine 5+.