If you told me I could only collect one brand, it would be Rolex. If you told me I could only wear one watch for the rest of my life, it would be my datejust.
If you actually consider a watch for its main purpose of telling the time and being reliable, I don't think there's any brand that has Rolex beat. Even if you put it up against a quartz or smart watch, those will lose to the Rolex in longevity and quality. Any high horology masterpiece will lose in toughness and reliability and, most likely, accuracy, not to mention the price.
That's what makes Rolex great: perfectly executed simplicity with a huge deal of care given to the wearing experience and reliability.