I'm not sure about this but I think you can use your own manager in order to keep spaghetti code to a minimum.

Demo: http://jsfiddle.net/8C5wR/

    function ClickManager(element) {
     this.el = $(element);
     this.check = function(){
       if (this.el.hasClass('class1')) {
        console.log('class 1 detected'); 
       }
       
       if (this.el.hasClass('class2')) {
        console.log('class 2 detected'); 
       }
       
       if (this.el.hasClass('class3')){
        console.log('class 3 detected'); 
       }
       };
    }
    
    (function(){
        $('.class1, .class2, .class3').on('click', function(){
          manager = new ClickManager($(this));
          manager.check();
        });
    })();​

Maybe others can weigh in to point out possible fallouts of this.