GetResponse is an all-in-one marketing platform. They offer email marketing, marketing automation, landing page, and marketing funnel service.
Leadpages is a service that lets online businesses create websites, landing pages, popups, and more to connect with their audience and make sales.
AWeber is an email service with email automation features. They use a drag-and-drop editor for creating their emails, and have plenty of templates to choose from.
HubSpot is a marketing automation and CRM suite that helps businesses market better through email, landing pages, SEO, social media, and content management.