I've had a Montgomery Ward's microwave for almost 21 years*, and it works as well as when it was new. I don't do much with it other than 'cook' frozen stuff, soup, and re-heat things. I once figured out that if you beat the hell out of eggs, throw in other stuff such as cheese, put everything in a bowl twice as big as it looks like you'll need, and nuke, you can make an easy and yummy soufflé.

The thing is, this was a great microwave which could be purchased 21 years ago, but I don't know if the current ones are as reliable.

*Damned thing's almost old enough to drink! There are likely younger Mudcatters.