What are the first 150 Pokemon?

Gen. I For Kanto region follow this link: http://bulbapedia.bulbagarden.net/wiki/Kanto_Dex

Gen. II For Johto region click on this link: http://bulbapedia.bulbagarden.net/wiki/Johto_Dex

Gen III For Hoenn region click on this link: http://bulbapedia.bulbagarden.net/wiki/Hoenn_Dex

Gen. IV For Sinnoh region follow this link: http://bulbapedia.bulbagarden.net/wiki/Sinnoh_Dex

Hope this helps