Sagas
Saiyan/Saiya-Jin Saga: Features Gohan being trained by Piccolo, Goku meeting King Kai, the arrival of Radditz, Nappa, and Vegeta, The death of Yamcha, Tien, Chaozu, Nappa, Radditz, and Piccolo, The fight between Goku and Vegeta, Vegeta going Oozaru, and the allmighty "Spirit Bomb".
Freeza Saga: Features the trip to Planet Namek, the training of Goku, the alliance of Vegeta, Gohan, and Krillin, the appearance of the Ginyu Force, the death of Vegeta, the death of Krillin, Goku going Super Saiyan/Saiya-Jin for the first time, and the "death" of Freeza.
Android Saga: Features Vegeta going SSJ, the arrival of Trunks, the death of Cyber Frieza and King Cold, Goku's return, Gohan going SSJ, the appearance of Androids 16,17, 18, 19, and 20. The death of androids 19 and 20. Goku recovering from his heart disease, Vegeta and Trunks going into training.
Cell Saga: Features the arrival of Cell, Vegeta going to a more powerful SSJ sub-level known as USSJ , the absorbtion of androids 17 and 18, the destruction of the heroic android 16, the formation of 2nd form Cell and Perfect Cell, Trunks going to a different SSJ sub-level known as USSJ2, Gohan going SSJ2, the death of Trunks, the death of Cell, and the revival of Trunks, 17 and 18 and the death of Goku.
Buu Saga:More information required to make summary.