Good alternatives to "some of the" (best)?

I'd use prime and first-rate or similar. [Edit] Can be combined with 'several' or 'various' if you like.

prime

[ATTRIBUTIVE] Of the best possible quality; excellent:
'prime cuts of meat'

first-rate

Of the best class or quality; excellent:
'first-rate musicians'

several

More than two but not many

various

More than one; individual and separate

References:
http://www.oxforddictionaries.com/definition/english/prime http://www.oxforddictionaries.com/definition/english/first-rate http://www.oxforddictionaries.com/definition/english/several http://www.oxforddictionaries.com/definition/english/various

Try bending the words to fit the description. For example:

Some of the most agile minds

Some of the fittest teams

Some of the richest companies

This way you can tailor the sentence and avoid repetition.

Plenty of options...

Amongst the elite, ...

Market leaders ...

There are premium quality XX that...