I recommend the ID-COOLING SE-914-XT because I’ve bought it, researched it, and I’ve been using it. For around $30 you get a sturdy cooler with a well-built single fan, a good-sized heatsink, and Intel LGA / AMD AM4 bracket support. It took my temps from about 50–60°C on stock down into the 30–40°C range, which is a massive improvement.