A good safe Login form

I would like to add a login and registration form to a Tax site. This would allow the user to login and go to the member area. I see several plugins but would like to know the best one out there.
I would like to either have a member register using a user name or email or we may give our members a member id such as their email to use to create an account. The goal is to have them login, sign up for a dinner meeting or seminar and pay using Paypal.

Thank you.
Debbie M,