it's important that you know that there are now two common hardware types - the older 32(?) pin ones and the newer SATA ones, so make sure you know which you need.
Hi,, this months 'pc advisor magazine' lists the samsung sh-s203 as the No1 unit in it's reviews ...costs �22. This is a SATA device (bearing in mind 'wickermanns' reply) But if your pc is not too old it ought to handle a SATA device.