What Are the Most Common Appliance Problems in a Home?

I've noticed that household appliances can develop different issues over time, from refrigerators not cooling properly to washing machines making unusual noises or dryers taking longer to finish a cycle. Sometimes it's difficult to know whether a problem needs immediate attention or can wait.
For homeowners in the area, what appliance problems do you encounter most often, and what do you usually look for when choosing Appliance repair Niagara falls ?