Pioneer SP-BS22-LR Bookshelf Speakers
These lovely speakers have recently been dubbed The Wirecutter's favorite bookshelf speakers, and they're not alone in this opinion. The speakers are currently rated 4.7/5 stars on Amazon (out of 43 reviews) and everyone seems to agree that the sound is fantastic. A few of these reviews have mentioned that the bass is so good it pretty much obviates the need to have a separate subwoofer.
With all this critical acclaim, we'd expect the speakers to be pretty pricey, but they're surprisingly affordable at $130. If you're in the market for excellent bookshelf speakers that won't break the bank, check them out.