Consumer Reports' Bob Markovich and his group sized up the popular Kohlers, as well as dozens of other toilets in the quest for the best.
The tests include dual-flush toilets. They have a lower volume flush for liquid waste. Another way to spot a water saver - the government's Watersense label.
"Toilets that use less water can save you more than $90 a year on your utility bills," said Markovich.
To see how well the toilets work, Consumer Reports flushed down a variety of objects, including sponges and plastic balls.
While many Kohlers did well in this test, its Devonshire K-3488 left some things behind.
"As for liquid waste, all the toilets rated excellent. That's a first in our toilet tests," said Markovich.
Testers built this structure to test for noise -- another problem with many toilets. A meter measures the sound level.
When all the tests were done, Consumer Reports named two best buys for $100 -- Aquasource AT1203-00 toilet available at Lowe's, and Glacier Bay N2316, a dual-flush toilet sold at Home Depot. They both have the Watersense label, so you'll be conserving water and keeping your utility bills down.
More information is available online.