I remember Joachim Johansson serving a 135 mph 2nd serve ace match point down.
Its on youtube somewhere. Lemme find it for you.
Edit: Here
http://www.youtube.com/watch?v=0zeza9uvscI
That may be the hardest 2nd serve ace.
But I can count 15 second serve aces for Sampras in his 14 slam victories.....
1990 US Open F vs Agassi @ 0-1
(0-0)
1993 Wimbledon vs Courier @ 7-6,6-6
(2-1)
1994 Wimbledon vs Ivanisevic @ 3-3
(30-0)
1994 Wimbledon vs Ivanisevic @ 7-6,2-3
(40-15)
1995 Wimbledon vs Becker @ 6-7,6-2,3-2
(0-0)
1995 Wimbledon vs Becker @ 6-7,6-2,5-4
(Deuce)
1995 US Open vs Agassi @ 6-4,5-3
(adv. Sampras)
1997 Aus Open vs Moya @ 1-1
(30-15)
1997 Wimbledon vs Pioline @ 6-4,0-1
(0-0)
1999 Wimbledon vs Agassi @ 6-3, 3-2
(0-0)
1999 Wimbledon vs Agassi @ 6-3, 6-4,6-5
(40-30)
2000 Wimbledon vs Rafter @ 6-7,7-6,5-4
(0-0 or 15-0)
2002 US Open F vs Agassi @ 5-3
(30-15)
2002 US Open F vs Agassi @ 5-3
(adv. Agassi)
2002 US Open F vs Agassi @ 6-3,6-4,5-7,5-4
(30-0)
These are the ones I know of. But I haven't checked 1993 US Open F vs Pioline, 1994 Aus Open F vs T. Martin, 1996 US Open F vs Chang and 1998 Wimbledon F vs Ivanisevic, as well as his 4 losses
But the highest I'm aware of in match is 4 in the 2000 Aus Open SF vs Agassi....
@ 4-6,3-1
(0-30)
@ 4-6,6-3,5-6
(30-30)
@ 4-6,6-3,7-6(0),6-6
(2-2)
@ 4-6,6-3,7-6(0),6-6
(4-4)
Right now the most in slam final is 3 (McEnroe 1982 Wim F vs Connors and Sampras 2002 US Open F vs Agassi), unless some knows different.