I really used to be big into Pokemon when I was really young, like 6 or 7. I only truly played sapphire but I 100% beat it, so I know up to the 3rd generation of Pokemon. My top 10 list is:
10. Sableye
9. Sneazel (or however it's spelled)
8. Waillord
7. Blaziken
6. Kyogre
5. Rayquaza
4. Machamp
3. Salamence
2. Dragonite
1. Tyranitar
Red, Blue and Green : Pikachu
Gold, Silver, and Crystal, Heartgold and Soulsilver: Suicune
Sapphire, Emerald and Ruby: Gardevoir
Pearl, Diamond and Platinum: Giratina
Black and White: Zoroark
Basically, I am a Dragon lover. They're so useful, since their only weakness is to Ice and each other (and a good Charizard or Blaziken easily takes care of the Ice).
Well, there's so many, but I'll just list some of my favorites.
Snivy (You saw that coming)
Pichu
Blastiose
All Eeveelutions except Flareon and Leafeon
Mudkip (Again, you saw that coming)
Genesect
WOOPER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I have changed my favorite pokemon. Its now Dragonair, on account on how awesome it looks, and the fact that I have a japanese Dragonair card that looks amazing. Even If I can't read it.
It'd be either Mewtwo or Moltres. Maybe both. Mewtwo is just really insecure like me, and that has caused us both to act the way we do, and Moltres is literally a pheonix, one of my favorite mythical creatures.
Charizard. It was evolved from my favorite of the first starters, as well as my favorite fire starter's evolved form. It had the best wins in the anime. It appears in the most boxart for games, at least in the states. And it flies...