The sentai concept is of 5 warriors who through one way or another can transform into a multi-colored battle squad to fight an empire or force that threatens the Earth. In 1975 Toei made their first "Sentai" show. While some earlier programs used a lot of sentai concepts, "Himitsu Sentai Goranger"(1975) is considered the first sentai show. It was followed by "JAKQ Dengekitai"(1977) which was by comparison to Goranger a flop. The sentai series then took a 1 year hiatus. Then in 1979 Toei created the show "Battle Fever J" which started the "Super Sentai" series which continues unbroken to this day. Later on Toei officially claimed "Goranger" and "JAKQ" as the first 2 in the series and "Battle Fever J" as the 3rd. The following list is of every sentai series and it's date of airing. Special thanks to Marc Miyake for some of the info.
1. Himitsu Sentai Goranger (1975)
84 Episodes
2. JAKQ Dengekitai (1977)
35 Episodes
3. Battle Fever J (1979)
52 Episodes
4. Denji Sentai Denziman (1980)
51 Episodes
5. Taiyo Sentai Sunvulcan (1981)
50 Episodes
6. Dai Sentai Goggle V (1982)
50 Episodes
7. Karaku Sentai Dynaman (1983)
51 Episodes
8. Chodenshi Bioman (1984)
52 Episodes
9. Dengeki Sentai Changeman (1985)
55 Episodes
10. Choushinsei Flashman (1986)
50 Episodes
11. Hikari Sentai Maskman (1987)
51 Episodes
12. Chou Zyu Sentai Liveman (1988)
49 Episodes
13. Kosoku Sentai Turboranger (1989) 51 Episodes
14. Chikyu Sentai Fiveman (1990)
48 Episodes
15. Chojin Sentai Jetman (1991)
51 Episodes
16. Kyouruu Sentai Zyuranger (1992)
50 Episodes
17. GoSei Sentai Dairanger (1993)
50 Episodes
18. Ninja Sentai Kakuranger (1994)
53 Episodes
19. ChoRiki Sentai Ohranger (1995)
48 Episodes
20. Gekisou Sentai Carranger (1996)
48 Episodes
21. Denji Sentai Megaranger (1997)
51 Episodes
22. Seiju Sentai Gingaman (1998)
50 Episodes
23. KyuKyu Sentai GoGoV (1999)
Currently Airing