PSYCHICS-ALAKAZAM is one of my favorites at the moment. My Meowth is incredibly helpful, so I keep him in my party as much as possible when exploring. Mewtwo cannot be understated, either, the super psychic he is. That's just from the first 150 anyway.
All starters are excellent too,so don't forget Venusaur!
I got all the Pokemon a person could dream of, and still working on more. If you need to know the truth, seek it out here, as I am obsessed with answering all the questions I can as best I can. I can verify Event Pokemon, too! My collection keeps growing!