TV for xbox gaming questions?

Alright i need some help for buying a gaming HDTV. First i need to know plasma or lcd. im going to get inbetween 42 and 60 inch. for LCD, how much difference does the hz make? is it worth getting a higher refresh rate or is it not noticable? (btw i play on xbox 360) what else.....yh ive seen 60 120 240 and 600 hz with lcds. different people in forumns say different things about them. is it just a personal preference thing for the refresh rate? thanks for the help