Clover Plastic Embroidery Hoop
If you're ready to invest in the best, here it is. Clover hoops are better for a couple of reasons: 1) the edge of the inner hoop grips the fabric more firmly that regular hoops, keeping it taut and 2) the screw cover keeps threads from getting caught and tangled.
When I cross stitch, I reach for my Clover hoop. It's just the Mercedes Benz of hoops IMO.
This is the 4.75" version. Treat yourself!