If you're asking what's the most sought after Rolex, no it's the Daytona. The Datejust is a classic though, so you can't go wrong with that.

It depends on your definition of "best". If you mean best all-around general use, it probably qualifies. The President cost considerably more, and most of what you get is prestige, the day of the week, and typically a lot more precious metal (gold, platinum, etc.). But as the cost of a Rolex goes up, so does its potential future value. The Daytona is the most expensive of current models, offering start/stop chronograph features and a lot of history. Again, it can offer a lot of precious metal content depending on which one you buy. At the other end are the very popular Submariner, GMT-Master, Explorer and Yacht-Master watches. These typically are either all stainless or have gold accents, but are not usually high-precious metal content watches. They are viewed as the really tough working models, built for severe abuse, and they hold up very nicely. They also tend to be less expensive, yet hold value very well. But back to the Datejust. I own a number of Rolex watches, and the one I wear most is my Datejust stainless and 18K. This is the classic Datejust style you have seen most, although it is more typical in stainless and 14K. I wear a Submariner or GMT-Master when I am doing more outdoor, sporty and abusive activities, and a solid gold President when I am going out on the town. So I would suggest you need to consider what you want the watch for, what YOU like best, and what your budget allows. One negative on both the Datejust and President models with gold links in the bracelets is that the links inevitably stretch over time, leaving a lot of space between links and a lot of loose play. This is annoying because it is expensive to get one fixed, and more to replace. I have never messed with fixing one -- I replace them. You can lessen the stretching by never wearing the bracelet tight. It should be loose, but not so much so that the watch head flops to the back of your wrist. I would also suggest you might want to look at a used Rolex from a reputable dealer (not ebay!), but pay close attention to how much side-to-side play is in the bracelet if it has any gold links (18K is even worse, because it is softer, but has higher resale). And select your Datejust caliber carefully. You want a quick-set movement and a sapphire crystal at a minimum. If the watch is missing either of these features, it will sell very low, but I would pass on it. With a used Rolex, verify that the bracelet and clasp are factory parts, not aftermarket replacements (usually from Italy) OR ELSE accept the aftermarket only if you are personally OK with that and the price is significantly less. You may want to get an extra link if the band is anywhere near snug. And I suggest you get a watch with box and original papers if possible. On resale, this can make a big difference in the value of the watch. If you want to cut the purchase price, get it without box and papers, but understand it will bring less in the future if you sell it. I did not try to cover the vintage Rolex possibilities, but I am guessing that is not what interests you. One final comment: not everyone is prepared to deal with a self-winding watch. Leave it undisturbed for a day and a half, and it will stop. Left for several days, you will have to reset the date (the motive for making certain you get a quick-set version) and the time. One cure is to buy an automatic winder -- one that periodically turns the watches for a few seconds during the day (not one that constantly turns). Keep that in mind. I hope this helps, but if you want to know more, I will be happy to try and help you out.