There are quite a few types of gutter leaf and debris guards available. They talk a lot about the various types on the Home Repair Clinic with home inspector Jim Salmon on WHAM 1180, Sat 6 to 10 am, and Sun 9 to 11 am. It seems most work to some degree, but the bottom line is, you will still have to clean them out eventually. None are 100% effective. Jim has some on his own property, and years of researching the topic. If you go to Jimsalmon.com, contact section near the top, you can send him an email question. He will get back to you with a concise answer. He would probably recommend a brand if you asked him.