When I bought my house, it came with a generic "Ding-dong" doorbell that sounded exactly like every doorbell you hear on TV. If I was out of the room when the TV went "Ding-dong", I was never sure if I had a visitor or it was just the TV. So I was regularly bolting up the hallway to the front door, only to find no one on the doorstep. It drove me crazy.
Having just bought a house, I was too hard up to buy a new doorbell, so I just rearranged things so that my doorbell now goes Dong-ding, rather than Ding-dong. The sound is quite distinctive and 16 years later I'm out of debt, but I feel no need to replace my unique sounding doorbell.