Sampras is great tennis player but Federer is the best. Sampras has no touch like federer. Not only that he cannot play from baseline. He cannot play more than 9 shots rally. He won so many GS because Wimbledon court were very fast. There were no more than 5 shots rally. Wimbledon has lost viewers interest so they slow the court to  see some baseline rallys. That is why Sampras has reached only one Roland Garros semifinal on the other hand Federer has reached one semifinal and 3 finals. He lost all the time with Rafa.

Clay court specialists like Vilas, Bruguera don't think Sampras a great player because Sampras cannot play from baseline. They think he is good but not a great. On the otherhand they think Federer is the greatest ever. He can play from baseline. He can serve and volley and he has unbeaviable shots. He is so dominent in the history of tennis. He has reached 10 finals straight. 17 GS Finals. The closest is 9 so far. He was unlucky in Finals with Nadal. If he had converted those break pts, he would have won in 3 sets. He didn't win early like Sampras because he was vegetiration before. He didn't get enough energy. If Sampras plays today, I am sure he won't win 14 slams. He knows that. Thesedays not only Wimbledon but US Open is slower than before. That is why though Roddick has the biggest serve in the history of tennis, though Roddick lost with Federer all the time. Fed knows how to handle big serve. Therefore, there is no comparision between Fed and Sampras.

Aggassi is media favourite. He knows how to work with media. But Fed and Sampras are way better than him. He himself said if he plays against Sampras in final, he cannot win. He has never won against Sampras in Final. He  has won in small tournment and quaterfinals of GS but not in Slams. He said Fed is better than Sampras. He said he knows how to play with Sampras but not with Fed.