SonVolt
Full Fledged Farker
Don't use pre-shreddred cheese as some have suggested. It's tossed in corn starch to "prevent caking" and doesn't melt properly. As others have suggested, grate your own Polly-O or Golbani blocks which are typically available in most large supermarket chains. You can also get a block cut from the Deli counter. This may not apply to you, but if you're somewhat new to pizza cookery it's probably not the cheese per se, but just the learning curve associated with learning to cook pizza as a whole. Don't worry, the curve is steep but fun and your pies get better over time!
Also, don't try and cook NY style pizza with Neapolitan high-heat.
Also, don't try and cook NY style pizza with Neapolitan high-heat.