craigslist - craigslist provides local classifieds and forums for jobs, housing, for sale, services, local community, and events

Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.

Facebook Marketplace - Marketplace is a convenient destination on Facebook to discover, buy and sell items with people in your community.

Eventbrite - Discover Great Events or Create Your Own & Sell Tickets

Bedpage - Bedpage is a classified ad posting a website that comes as the alternative to Backpage and offers almost all the major services to post for multiple categories.

Bigtent - BigTent is a web-based organization and communication portal for groups.