As Mrs Petit already told you, irregular verbs don't have to be boring; here you have some games you could be playing while practising .
http://www.visi.es/boxexercises.html
http://www.manythings.org/wbg/verbs_past7-mw.html ( two players for this one)
http://www.cliknlearn.net/ ( 4th ESO ->Intermediate-> either the Verb Tree or the Verb Burst games)
http://www.english-online.org.uk/games/gamezone2.htm