〜の至り／〜の極み

光栄の至りです。

Kōei no itari desu.

I am honoured beyond words.

の至り takes a positive feeling — the superlative of a formal address

贅沢の極みと言えるでしょう。

Zeitaku no kiwami to ieru deshō.

You could call it the height of luxury.

の極み takes either, and is more neutral than の至り

受賞の挨拶で よく耳にします。

Jushō no aisatsu de yoku mimi ni shimasu.

You hear it in acceptance speeches.

That is one of its few living contexts