What is the best use of salvia?

It's good in risotto.

Salvia is one of the stronger herbs, best used sparingly in cooking. It's famous as one of the key ingredients in stuffing for poultry. It also has medicinal qualities. Sage tea is said to be good for sore throats.

Delicious as a flavoring in butter sauce for ravioli filled with ricotta and spinach.
I 'fry' a few leaves quickly in the butter/olive oil mix and take them out to drain. Then break a few into the butter/oil and turn the heat down. Let the butter get a little brown. When done, pour it onto the ravioli and top each person's dish with one of the fried leaves. Deliscious.

-Sada Sat
-www.yogaborgo.com

And who can forget that classic hit of yesteryear 'Salvia's Mother' by Dr Hook and the Medicine Show ?

Large sage leaves dipped in beaten egg and breadcrumbs then fried as a tasty, crunchy side dish...

I often make the sage butter sauce described by Sada Sat but then saute a bit of chopped onion and sliced zucchini with the sauce before mixing it with the ravioli or tortellini. Its been a hit every time

I nominate Saltimbocca.