Tell us about yourself!
I have traditionally used a reverse biased rectifier diode across the input. It presents a short-circuit to reversed input voltages, but more often than not the source supply either has a fuse or is a modern switching supply with short circuit protection (hiccup mode). The advantage this scheme offers is that there is no voltage drop or impedance in the power path at all (normally). In some cases, you can substitute the rectifier diode for a TVS diode to get some measure of transient voltage excursion protection as well.
The Hamilton Beach oven is soldiering on just fine. If I have any complaint about it it's that it doesn't heat quickly enough for a RoHS profile, but I'm not sure any 120 V toaster oven would be able to do that, at least not without extensive modifications. Apart from that, it's doing just fine.