i don't check regionals that often, but i do hope my answer could be still useful...
so, no doubt that Swatch Snowpark Mottolino in Livigno is one of the best, if not the best snowpark in Italy, it has a sick overall set-up
other really good ones are Bardonecchia, in the north west, and King Laurin in Seiser Alm, near Bolzano
Some other snowparks you could check: Madonna di Campiglio, Kronplatz, Obereggen and Gentlemen's park in Senales...
even though it's in italian i think you could get some more infos here:
http://snowmap.snowbox.it/pages/snowpark.php