I grew up following tennis in the mid to late 70's while I admit that the players then would struggle against today's crop (for the most part), there are many aspects of that era that I miss.
In true to list form (what else) I have outlined twenty. These are:
1. Jimmy Connors vs Bjorn Borg on any surface
2. Ilie Nastase's temper tantrums (he knew how to throw them)
3. The finesse of the wooden racket.
4. The focus of Arthur Ashe
5. A little kid called Johnny Mac upsetting the Applecart
6. Chris Evert vs Billie Jean King
7. Characters like Vitas Gerulatis, Harold Solomon and Eddie Dibbs.
8. Mexico's big name player Raul Ramirez (don't think they have had one since)
9. A very young Martina Navratilova still playing for her country of birth (Czechoslovakia)
10. Jimmy Connors rowsing a crowd.
11. Borg's ice cool temprament (its a great pity that his life has fallen apart lately)
12. Argentinian superstar Guillermo Vilas (he often played in South Africa)
13. The South African pairing of Bob Hewitt and Frew MacMillan (remember his cap) dominating the doubles at Wimbledon.
14. Virginia Wade winning the Wimbledon Ladies Singles in 1977 (last Brit to win a Single's title at Wimbledon)
15. US Opens at Forest Hills
16. Australian Opens on Grass that never seemed to attract the big name players.
17. John Lloyd and Buster Mottram carrying the Union Jack at Wimbledon.
18. Long Rallies
19. Fewer Aces
20. More serve and volley players around.