1. Victoria (sorry, know too much about her for comfort. In my series of games based on modern politicians though she represented the ever-present threat of Tony Blair, since I know someone who reckons he is Queen Vic reincarnated. Allegedly.)
2. Isabella has to die so I can get Buddhism first.
3. After that Mansa Musa because of the technological capacity.
4. Julius Caesar gets too powerful if you let him be too long.
5. As does Augustus.
6. Montezuma is a pushover but has to be eliminated nevertheless.
7. Tokugawa. This one is for the Bridge on the River Kwai, courtesy of my Grandad.
8. There goes Shaka too.
9. Hammurabi...no more.
10. Genghis usually has to be stopped before he can get too big, but he's useful enough early on to wipe out a civ or two first so he is usually the target if I can get gunpowder long before anyone else can.
Honourable mention to Justinian (usually builds well away from me so he usually gets done in last) and to Huyana Capac or Pacal II (just call him "Pacman") because if Montezuma isn't available, I usually need someone to wipe out with a clever plague or two.