THE NOUN PROJECT.
This is a pictogram-lover’s dream. A website with over one million icons, ready for use. thenounproject.com
Founded with a Kickstarter campaign in 2010, initially they posted public domain icons.
Below, The Noun Project logo.
Everyone has access to every icon. Free members need to give a credit to the designer, and paid members ($39.99 per year, or $9.99 per month) get unlimited royalty-free licenses. Below, are some example sets, but explore the collections yourself.
Raccoon Emoticons by AomAm.
Birds by Georgiana Ionescu.
Buildings by Made by Made.
People by Vectors Market.
The Noun Project blog: https://thenounproject.com/