The Korky 6000BP leads our ranking. It is a wax-free rubber seal, so there is no sticky mess, and Korky says it adapts to above-floor, level and below-floor flanges and to both 3 in and 4 in drain pipes, the widest fit on this page.
Its biggest advantage is that you can reposition the toilet during installation. With a wax ring, setting the toilet crooked or lifting it once means scraping off the wax and starting over with a new ring. With this seal you can lift, adjust and set again, which takes the pressure off a first-time installer.
The kit includes bolts and 4 retainer washers, weighs 0.3 lb, is made in the USA and carries a 10-year warranty, the only stated warranty here. Korky describes its red rubber as long lasting. For most DIYers replacing a toilet seal, it is the best choice on this page. Clean the old wax off the flange completely before fitting it, and tighten the nuts evenly until the toilet sits firm without rocking. Do not overtighten, since that can crack the porcelain.