Congrats to Fed, although it would be 'sweeter' if he had completed the number of weeks on a "consecutive" basis. Fed had the chance then to make it consecutively. Water under the bridge.
Federer has reached his 300+ weeks in only three different periods as #1. Sampras used 11 for his 286 weeks. That is, amazingly, still not the record. McEnroe was #1 14 (!) times for his 170 weeks. Four of those were one week only, and five more were less than five weeks. Much back-and-forth those days. Today, Fed's current streak which will end at 17 weeks is the shortest since Roddick's in 2003-4.