There is a solution, though. You can create a text widget with a title like "Most Widely Read" or "Recommended" or "Personal Favorites", and then below that you can create links for the posts you want to have featured.
I have links like these in the footer of my blog, and I update them periodically. This helps people find older items on my blog that other readers have liked, or that I think are examples of my best writing.
Text widgets are hard to use at first, but there are instructions about how to embed them with the necessary HTML on the support page.
You can look at the summary statistics for your posts to figure out which ones have gotten the most all-time views.
my blog is Our Polity at http://susanbarsy.com