Gmail has much to offer: 10 GB of free space, labels instead of folders, conversations, integration with many services and much more. There are two editions to choose from:
Register for a regular and free Gmail account. Your Gmail address will be like firstname.lastname@example.org.
your own domain
If you prefer to have your own domain, then apply for a Google Apps account here. The Gmail address will then be email@example.com, where yourdomain.com will be a name you pick.
Mailplane for Mac
Mailplane is the best way to use your new Gmail account on your Mac. Learn more here.