1. WP-Events – An event calendar with approvals.  Free version is good for most people, but the paid version allows you to customize your messaging more.  A well-supported and widely-used plugin.
    http://wp-events-plugin.com/
  2. Form Maker by Web Dorado: Great form and very easy to use.  Saves entries instead of just emails them.  Free unless you have more than 7 fields.
    https://web-dorado.com/products/wordpress-form.html
  3. Give WP – Online donation form:  We are also using this online giving form for donations non-profits and member organizations.  The price depends on the payment gateway you use, so between $12-25/month
    https://givewp.com/