Full disclosure: IMPACT is a HubSpot partner -- but that's not why they're included here. IMPACT's landing pages have long been a source of design inspiration. I love the simple layout of the page, from the large headline copy and detailed featured image, to the outline that surrounds the form, to the colors and fonts that are very pleasing to the eye.
That small PDF symbol over the feature image helps set expectations for what format the download will be in. The arrow in front of the subheadline helps further direct your attention to important copy they want visitors to read. Like IMPACT, they also have an auto-checked box to subscribe to their newsletter on their form -- which, if turned into an opt-in check box, is a great way to increase subscribers. All of these small, seemingly insignificant details help bring together a solid, admirable landing page design.
Imagine an autoresponder that doesn't just send emails, but allows you to track which channels your visitors are coming from, segment them based on actions they take and who they are (what they do in your funnels, how socially connected they are, what they purchase and more!), create custom follow up sequences (email, text messages and more!) for each visitor and FINALLY see the TRUE Lifetime Value of each of your customers!