Below are links to Quia games and activities that will help with unit review or even with strenthening vocabulary and practicing verb conjugations. When you get to the quia site, look around and find the appropriate review materials for you. Don't forget to scroll to the bottom of the page where I provided useful links for more games and activities!
For Spanish 2:
For Spanish 3: http://www.quia.com/pages/maniaci3.html
For Spanish 4: http://www.quia.com/pages/maniaci4.html