Your life. Your love. Your wife! We all know it's not true, but she's still quite alright. Don't let yourself get dragged into the hype of 'best in the world', it can put an unnecessary strain on even the strongest relationships.
Instead why not agree that she's OK? This funny t-shirt, stating 'World's Okayest Wife' is a great gift for your wife, be it anniversary, birthday or Christmas.
Unless of course she doesn't have sense of humour, in which case you might want to run!