Yeah, the "beige brick" power supply is what put a lot of C64s out of commision. No power, no working computer!
The trapezoidal black "heavy duty" power supplies with the Commodore 64 label on top are the ones to get if you are a collector. They can at least be repaired and don't die easily.
Failing that, there have been a few aftermarket repairable supplies, but collectors mostly have them. They don't show up on ebay often at all.
There is also a company that is producing a drop-in C64 motherboard clone which uses DC power, and is more power efficient in general, and can flip between NTSC and PAL modes. You have to supply your own 6510 CPU and SID chip however.
I have a number of C64s of different vintages, including an SX64. It's a repaired brown "breadbox" that gets the pride of place under the TV because that original model is iconic. It also takes up less shelf space than the 64C models.
I still have a "lumbering hippo" 1541 that's been modded for parallel speed disk dumping, and a few spare datasettes for dumping the occasional rare tape game I come across. ...and yeah, Telengard was a lot of fun! Ok, so it doesn't compare to Skyrim, but man, back in the day.... :)