How you rank them is entirely up to you; it can be based on how much you like/dislike them, how strong/weak they are, etc. Also, include your favorite Pokemon of each type (ties are OK).

I'm not really taking balance into consideration for my ranking.

1. Water - Gyarados or Starmie
2. Grass - Venasaur or Exeggutor
3. Psychic - Musharna
4. Ghost - Banette or Chandelure
5. Normal - Miltank
6. Ice - Jynx or Mamoswine
7. Poison - Muk or Weezing
8. Dark - Umbreon
9. Steel - Steelix
10. Flying - Noctowl
11. Bug - Vespiquen
12. Ground - Donphan
13. Fighting - Machamp
14. Fire - Ninetails
15. Rock - Onix
16. Electric - Raichu
17. Dragon - Flygon