I'm in the minority here, but the Dyson I've got has been disappointing. I think it actually has less suction than the Dirt Devil it replaced.
Blasphemy! Kill the non-believer!
I agree to an extent, I do find our Dyson very good. However, we have wooden flooring throughout so massive suction isn't really that important. Instead I like the Dyson as it is light, compact and well made.