I confirm the opinion #8, 10, 13, 17 and 25 krab. Himitsu Sentai Goranger is the first real sentai serie and longest one too. However, the first sentai that had a huge robot for fighting with giant monsters is Battle Fever J which was broadcasted in Japan in 1979. The further information can be found in http://www.thai-toku.com http://www.supersentai.com http://www.japanhero.com
Khun ข้าวหลามหนองมน krab, you might misunderstand something. The posing you mentioned above isn't a Goggle Pink' one but belongs to Denji Pink. I don't think that Goggle Pink เอาหลังข้อมือมาแตะกันบนหัว งอเข่าน้อยๆ ข้างนึง when she made any posing.
For me, Chodenshi Bioman is the most favorite and best sentai serie krab.