I had a Mr Frosty but after spending ages grating ice cubes (I thought it would be like a proper machine with ice pouring out of the front, as in the picture) I wasn't allowed to use the syrups that came with it because 'chemicals'. I also got a chemistry set with a microscope, which I also wasn't allowed to use as it was also full of 'chemicals'.
I did have the best Christmas present ever though, that I still occasionally look for on eBay - a Madam Rosa set. It was a big dark blue glittery crystal ball, on a mount with batteries in and a slot in the side.
It came with a deck of cards with invisible ink pictures printed on them. Your 'customer' (I used to make my family take it in turns to crawl into a tent that I rigged up by draping a sheet between two armchairs) would select a card, and you'd slide it into the base of the crystal ball.
The set came with two huge clunky 'ruby' rings, one of which had a magnet in it. You waved your hands over and around the crystal ball, until the magnet hit a connector spot which caused a light to switch on inside the ball.
You peered (in a mystic fashion) through a red plastic pane at the top of the crystal ball, and the red light would make the picture appear on the card - instant fortune! It came with a little booklet comprised of stories that you could use fit each picture. It was so simple and so
Incredibly effective. It was honestly a work of toy genius.