there are 4 nonstop options from the NYC area to Vegas right now. Delta, Frontier and jetBlue from JFK. Delta and jetBlue on their basic economy fare will both allow you to have a normal size carry-on after September 6th. Before that, jetBlue will not have that. Both Delta and jetBlue have free wifi if you are a member of their loyalty program (free to join). Both have multiple flights a day. Both have decent legroom and inflight entertainment system. Would not fly Frontier. 1/2