I highly recommend MailerLite. I’ve used Aweber in the past, and have worked with MailChimp for a client, but like MailerLite the best. It has all the features of the big boys (ie: ConvertKit) but is much less expensive. In fact, it’s free for up to 1,000 subscribers! You can have multiple webforms with different freebies attached, and it even creates landing pages for you. Great tool!