June 5-9. A lot of the country will still be in school so you'll miss the summer crowds. March may have some spring breakers. Baseball season so you could have the option of hitting a dodgers or angels game if you're into that sort of thing. Great weather.
June - although compared to WDW, there's really not a bad time to go to Disneyland (excluding the major holidays). We went in July during peak season and the crowds weren't bad at all and weather was great!