The best way to check your ranking for your website is to do a search on whatever search engine you're trying to rank on for whatever search term you're trying to rank for.
However, if you're trying to measure your traffic, then use your site logs from your hosting provider, which should be the most accurate. Other options include Google Analytics, Microsoft's Analytics, and any number of paid analytics programs.
I havent come across any tools and calling alexa accurate make me laugh (sorry its not your fault) alexa toolbar users tend to be techy people who spend there time on techy websites so say you have a site to do with buidling supplies you may find a site with half the traffic is ranking top 100000 whilst you cant make the top million!