I just sort of skimmed all the replies, so sorry if I repeat an answer, but:
I had this question a few days ago.
I used:
A Charizard level 45,
Articuno 50
Zapdos 50
Raichu 41 (With thunder)
Golem 58+
Alakazam 58+ (Psychic)
To be honest, you can kill the first person with Thunder or...