We are proud new owners of a Shark Navigator upright vacuum. The vacuum claims to never lose suction just like a Dyson, and my mother-in-law, who's used both vacuums confirms that the Shark is just as good. Look at how much stuff it sucked up on its first test run:
All of that is just from our living room rug, which is fairly new, and my son's bedroom. Yuck.
We got ours from Bed Bath & Beyond. It's $150 at BB&B, which is $30 cheaper than what it costs at Target, plus you can use one of their 20% off coupons on it. With the coupon it cost us $130, a mere fraction of what a Dyson costs.