It largely depends on the (professional) context, but in the UK many people use a friendly 'Best wishes', 'With best wishes', or the shorter (terser, but not necessarily unfriendly) 'Best'.
Starting or ending an email just with someone's name is generally considered rude in the UK – or very serious, e.g. if you're about to severely reprimand someone. However, if you're good friends (or, as #5 suggests, if you've already exchanged numerous emails with that person in a short space of time), it's not unusual to start and end even with just initials ('D – have you seen this? F')
'Love': between people who are very close, for instance if you're emailing your wife's mother.
'Yours sincerely': rarely used – normally only in very formal circumstances, i.e. when the email is essentially a letter (perhaps for a job application); the same goes for 'yours faithfully', though you normally use that one only if you don't know the name of the person you're writing to (i.e. if you start with 'Dear Sir' or some such)