If you are actively looking to expand your connectivity, without regard to amassing prospects, any size of a networking event would work. Chambers of Commerce, business associations, entrepreneur societies, can all be a source of networking opportunities.
Another couple good sources of local networking opportunities are Meetup & Eventbrite. Just search for Business or Networking.
If you are a shy networker, smaller, more organized events may be more to your liking. I don’t like the larger events. I don’t like being hit on by thesharkswho are out to make a quick sale, not into developing a relationship. I have better luck in connecting with smaller networking opportunities.
If you would like to learn more about networking, whether shy or not, I would recommend by book: Tips & Techniques for Moving from Shy to Sly!
Thanks for your question!
as originally answered on Quora.com