I'd have to say sagittarius.... I'm a sag and my hubby is a leo and we have amazing sex and a very pasionate love. (we've been together for almost 6 years!!)
I'm a Leo and the best (also most complex, deep, etc.) relationship I've had, or could imagine having again, was with a Gemini. Of course, I haven't been with every sign yet. I look forward to an even better match.
i am a leo and my boyfriend is a cancer....we always get along and we almost never fight. He is the best thing that even happened to me!
Aquarius is the pole opposite of Leo so they go together well. Air signs go well with fire signs. I wasn't good with Pisces or Taurus. Going with other Fire signs may take some work but its worth the effort. Never a dull moment with a Leo