Unicode Circled Numbers ① ② ③

White Circled Number

These are specifically sans-serif:

Black Circled Number

These are specifically sans-serif:

On black square:

Double Circled Number

Number with Period

Parenthesized

Chinese Circled Number

Parenthesized Letters

White Circled Letters

The Ⓜ means Metro.

Black Circled Letters

Here's a screenshot of what they look like. May be different in your browser.