Disk Utility cannot format the drive as NTFS.
Which file system to use depends on how you plan on using the drive. If you're going to be putting huge files on it (i.e. single files bigger than 4GB) you MUST use NTFS and miles01110's suggestion to enable read/write support on the Mac side. Otherwise, you can use FAT32, which Disk Utility CAN create (make sure you select MBR as the partition scheme, and MS-DOS/Windows as the format).