3. IBM Model 5150
IBM, one of the earliest and most popular makers of computers, revolutionized the computer industry with its innovative computer models. IBM Model 5150 was one of the first computer models to be popular enough to reach the homes and offices of people after its release in 1981. Interestingly, the Operating System of the model, DOS was sold as a separate commodity to other computer making companies. DOS later became one of the most common operating systems out there.