I don't think you can find a single perfect example because that will be based on that particular company in that particular industry. But what you can do is look for a series of landing page best practices. My book, The Best Damn Web Marketing Checklist, Period! includes many of those best practices that directly affect PPC as well as other areas of marketing. You can also find the free cheat sheet at www.webmarketingchecklist.com. You also might want to check out this article here: http://searchengineland.com/why-my-optimized-landing-pages-trump-your-seo-and-ppc-landing-pages-everytime-167430 as well as the book Landing Page Optimization by Tim Ash.

I'd focus on learning landing page best practices and applying them to your specific product and audience. There are tons of resources out there to help you (check out this webinar specifically geared toward optimizing PPC landing pages: http://webinar.unbounce.com/ppc-landing-page-hacks).

I'd be happy to set up a call and help you discover some opportunities for improving conversion if you'd like to discuss further.

You can find lots of examples in this PPC Landing Page Gallery: http://www.ispionage.com/landingpagegallery.

It's important to understand the science of what people respond to and what draws their attention in terms of visuals, headlines, word choice, placements.
A couple of resources I would point to would be http://www.wordstream.com/blog/ws/2015/06/15/landing-page-inspiration (different strategies, examples of landing pages and what makes them stand out) and this infograph on color - https://blog.kissmetrics.com/color-psychology/?wide=1.

I hope you find them helpful. I do design work if you'd like to set up a call and discuss options.