Off the top of my head, without looking at Wikipedia, there are a few "Stands Alone" titles that immediately come to mind. In my opinion, these are the best:
1. Rod Laver - 2 Calendar Year Grand Slams
2. Martina Navratilova - 9 Wimbledon titles in singles
3. Margaret Court - 24 Grand Slam titles in singles, 2 Career Boxed Sets, and 64 Grand Slam titles combined in singles, doubles, and mixed.
4. Novak Djokovic - 23 Grand Slam titles in men's singles
5. Steffi Graf - The Golden Calendar Year Grand Slam
6. Roger Federer - 8 Wimbledon titles in men's singles
7. Rafael Nadal - 14 French Open titles in singles
I don't think there are any other "Stands Alone" titles that are more impressive. Players other than Rod Laver won the Calendar Year Grand Slam but no one did it twice. If Novak wins two more Grand Slam singles titles, then Margaret still has two other "Stands Alone" titles to keep her on this list. Martina won the greatest tournament in tennis more than anyone else and Roger gets to hold onto his precious men's record at the Big W for now. Steffi's Golden CYGS is just pure dominance and Rafa's French Open record is hard not to remember and acknowledge despite happening on dirty red clay. Not on this list are Borg and Serena, both larger than life figures but they hold no "Stands Alone" title that I can think of. These 7 players, to me, hold the greatest "Stands Alone" titles of all time, if I never saw any of these players hit a ball, I would say that based solely on what's in the record books, Rod is the GOAT but it's still a tough call.
1. Rod Laver - 2 Calendar Year Grand Slams
2. Martina Navratilova - 9 Wimbledon titles in singles
3. Margaret Court - 24 Grand Slam titles in singles, 2 Career Boxed Sets, and 64 Grand Slam titles combined in singles, doubles, and mixed.
4. Novak Djokovic - 23 Grand Slam titles in men's singles
5. Steffi Graf - The Golden Calendar Year Grand Slam
6. Roger Federer - 8 Wimbledon titles in men's singles
7. Rafael Nadal - 14 French Open titles in singles
I don't think there are any other "Stands Alone" titles that are more impressive. Players other than Rod Laver won the Calendar Year Grand Slam but no one did it twice. If Novak wins two more Grand Slam singles titles, then Margaret still has two other "Stands Alone" titles to keep her on this list. Martina won the greatest tournament in tennis more than anyone else and Roger gets to hold onto his precious men's record at the Big W for now. Steffi's Golden CYGS is just pure dominance and Rafa's French Open record is hard not to remember and acknowledge despite happening on dirty red clay. Not on this list are Borg and Serena, both larger than life figures but they hold no "Stands Alone" title that I can think of. These 7 players, to me, hold the greatest "Stands Alone" titles of all time, if I never saw any of these players hit a ball, I would say that based solely on what's in the record books, Rod is the GOAT but it's still a tough call.