We bought the dyson hoover for our son when he was 18 months old from Argos. It's the one toy that he played with every day from 18th months until he was about 2 and a half. He still plays with it now, just not quite so often!
We have had one problem in that after a few weeks of use, when on the suction setting, the hoover makes a very loud unpleasant continual noise. We took the original dyson back to Argos, and got a replacement under the guarantee. However, the replacement dyson now does exactly the same noise. So we've kept it as our son loves it so much, but just don't use that setting. He loves to get it out when I'm doing the hoovering. He is nearly 3 now and does a little help with the attachements but apart from that he can operate it all himself.