I've owned 3 360s. A Halo 3 Edition, a Halo Reach Edition, and a 10-year-old one that was pried from a demo kiosk when the store I worked at got rid of the demo units after a planogram change.
The only one that ever had a problem was the Halo 3 one, which E74'd on me. However that was under warranty, so I was able to get it fixed for free (unfortunately the casing got chipped a but in transit). The main reason I upgraded to the Halo Reach one was the storage capacity, as 20 GB was no longer anywhere near enough, and for the price difference between a new hard drive and a new, limited edition console with an even bigger hard drive, it was worth it for the complete upgrade.
The kiosk console, which was an original 2005 model, never broke down once in its years of operation, and was eventually gifted to some of my cousins after being reformatted. In fact, the only component of the Kiosk that ever broke was the monitor, whose backlight burned out after about 6-7 years and needed replacement.