There are many quality grout sealers available on the market today, including AquaMix, Stonetech, Tile Lab and Homax, among others. As of August 2015, the best selling grout sealer on Amazon.com is Homax Group Inc 9535 1 Step Grout Sealer.
The Homax Group Inc 9535 1 Step Grout Sealer is reasonably priced compared to other grout sealant options and is rated as 4.3 out of 5 stars on Amazon.com.
An independent test by the North American Tile Cleaning Organization found that Stonetech Bulletproof sealer, manufactured by the DuPont corporation, was the most effective at sealing tile grout. However, this was also the most expensive of the sealers that were tested.