Sampras won 7 Wimbledon out of 8 - from 1993 to 2000. Federer also won 7 but from 2003 to 2012.
Here's a look at their grass achievements:
Roger Federer’s opponents in the Wimbledon finals:
Mark Philippoussis (2003) – 1 Time Wimbledon finalist
Andy Roddick (2004, 2005 and 2009) – 3 time Wimbledon Finalist
Nadal (2006 & 2007) – 2 time Wimbledon Champion
Murray (2012) – 1 Time Wimbledon Champion
Pete Sampras’ opponents:
Jim Courier (1993) – 1 Time Wimbledon finalist
Goran Ivanisevic (1994 & 1998) - 1 time Wimbledon Champion and 1 time finalist
Boris Becker (1995) – 3 time Wimbledon Champion
Cedric Pioline (1997) – 1 time Wimbledon Finalist(Sampras was coming off beating Becker and Pioline was coming off beating Michael Stich)
Andre Agassi (1999) – 1 Time Wimbledon Champion
Patrick Rafter (2000) – 2 time Wimbledon finalist
In his prime, Sampras was almost unbeatable at Wimbledon winning 7 out of 8 in succession while staying at No. 1 from 1993 to 1998 but he also, beat different opponents and met with Goran only twice.