I often use:

Bien à vous

or:

Bien à toi

which is closer to Yours truly I guess.

In business or university context, I tend to use:

Cordialement,

Moreover, if I am thankful and want to convey this stronger feeling, I use:

Bien cordialement,

I often use the adverb for cordial:

Cordialement,
<Here my email signature>

For an “almost friend but not really friend”, I use something similar to kindly:

Amicalement,
<Here my email signature>

Taking the first few mails in my inbox, we have:

Bonne journée,

Bonne fin de semaine,

Cordialement,

Quite often, nothing.

But mostly, as this is the one included in the official company signature:

Meilleures salutations,