There are a few really good website rankers by subject category, by country, and by other factors. Some are free, but most have a charge. Many other tools and services besides Alexa offer website traffic and ranking analysis. Examples include Similarweb, Semrush, and Ahrefs.
Alexa: http://www.alexa.com/topsites defunct: Alexa's website ranking service was discontinued by Amazon on May 1, 2022. The service used a system that ranked websites based on their estimated average daily unique visitors and page views over a three-month period. Although the service is gone, third-party tools and alternatives still provide similar website traffic and ranking analysis.