Here I'm trying to discuss about optimal performance but absolute value for money Brand: Must be top brand offering warranty at least for 2-3 years, don't confuse Top brand is totally different from popular brand(cheaper its popular will be in India most here don't mind performance). These days manufacturers are offering 5 year warranty too. Connection: Can be two ways Firewire or USB. These days USB is sported high cause can be connected with most computers. But choose what best suits you cause Firewire's performance is unmatchable to USB. Speed: Seek time <10ms | Buffer Size > 4Mb | RPM : 5,400 - 7,200 (Please keep in mind values here are for optimum performance, go higher if you can spend) Size: Must be greater than 80GB, as said before if you can spend go for bigger but not biggest it will degrade performance. Search: If you reading this post its obvious that you are searching sites for idea, but don't stop here. Go to Manuf
free from spelling and grammatical check, just keepin it human