Here is a boss list for the game, Pokemon Black and White version. I will only include human bosses, the legendary pokemon have not been included. 42 bosses in total.
The List
1. Cheren - 7 times
2. Bel - 5 times
3. N - 4 times
4. Dent/Pod/Corn
5. Aloe
6. Arti
7. Kamitsure
8. Yacon
9. Fuuro
10. Hachiku
11. Iris/Shaga
12. Shikimi
13. Renbu
14. Giima
15. Caitlin
16. Final N
17. Ulitmate Geechisu
Post-Game
1. Bel fight
2. Cheren fight
3. Nobori
4. Fudari
5. Nobori + Fudari
6. Shikimi 2
7. Renbu 2
8. Giima 2
9. Caitlin 2
10. Morimoto
11. Cynthia
12. Super Adeku
Others: 7 Legendary bosses, 1 Pokemon boss
