Hewitt, Ferrero, Roddick, Agassi and Chang all started with a POG.
I am sure lots used some sort of Prestige. I find it a shame that if this question were to be asked in 10 years time, the answer would be "Babolat", times are changing though.
Saw Agassi play & win the Nevada Open in Reno 1986 he used the POG oversize no tourna-grip & he used a cable grommet instead of the rubber band he now uses. Saw him as a kid in Las Vegas when they had the Alan King Classic he was using the Rossignol Stratos wood that TW sells on the vintage site.
Why is it a shame? It's just good business strategy on Babolat's part. They're being aggressive and going out there and getting people to play their racquets. They give out tons of sponsorships and commit to the junior players and College programs. This in turn breads brand loyalty for when they become pros.
Roddick used a prince 760 longbody or something when he was 14 or 16. It was a gray racket, and was a longbody.
Then I saw a picture of him using Prince Micheal Chang longbody (original version).
I don't know if Roddick would have ever used POG. It seems like he likes longbody
Xavier Malisse used to use Micheal Chang LB MP as well. One time, he broke a strong and had to borrow Hass's racket (Premier tour) during practice session. Xavier seemed to like it a lot, and was asking if they had it in longbody.