My friend is convinced that the last few classic matches happened between 2001-2004, the only lately one would beat Venus vs Davenport in the SF of 2005 Wimbledon, but I think that only Sharapova (I'm not being biased at all) had some classics matches since she started tennis...
-1st: The whole Wimbledon 2004 is a classic, she played amazing matches as a young player, not even a darkhorses...just remember the SF against Davenport (2-6 7-6(5) 6-1) or just how just stormed in the final against Serena (6-1 6-4)
-2nd: SF against Serena at the AO 2005 (6-2 5-7 6-8)
-3rd: Probably the Wimbledon 2005 SF against Venus (6-7 1-6)
-4th: The USopen 2004 most likely her win against Henin in Final (6-4 6-4) and her match against Mauresmo in SF (6-0 4-6 6-0)
-5th: I think The Biggest one, is Henin vs Sharapova at the YEC in 2007 ( 7-5 5-7 4-6)
-6th: There is also a potential classic match at this year AO, the Quarter final against Henin (6-0 6-4) would be a good one.
I think that the only reason why my friend can't see one of those matches as classic it's because they aren't old enough
..what is making a classic match it's when it is getting old and that we still remember them.
PS: I'm not saying that they are ALL classics, but to me they could be.