Apple's iMac has long been the gold standard of all-in-ones. It's also been years since the design has changed. That has left plenty of room for innovation by other companies, and Lenovo's Yoga AIO 7 is a great example. Its 27" display is 4K, not 5K, but it can rotate to portrait orientation for viewing larger webpages (or giant vertical videos). It's powered by AMD Ryzen CPUs paired with Nvidia RTX graphics and will be widely available next month.