Samsung and Seagate are the two makes to go for.

IDE drives are getting fewer in number now though as SATA drives have completely taken over.

When looking for an IDE drive, if you are using older hardware you need to be aware of what protocols, speeds and HDD size the IDE controller can work with. Very old P2 and P3 motherboard IDE controllers can sometimes only address the first 32GB of HDD space on a drive, whereas other P3 and P4 boards 128GB. These limitations can normally be overcome using software patches available from the HDD makers own websites if needed.

Also try to get a drive with an 8MB Cache. Many IDE drives have a smaller 2MB cache and this makes a big difference to read and write speeds due to the smaller buffer. However if that is all you can find it isn't too much of an issue.

Also try to get a drive with a spin rate of 7200RPM.

What sort of sized drives are you thinking of getting?

Seagate 80GB drives are around £28.
Seagate 160GB drives are around £35.
Western Digital 250GB are around £45.
Western Digital 500GB are around £60.

I've not seen an IDE drive larger than 500GB, and £60 is a lot of one these days when you consider you can buy a 1TB SATA drive for the same price.

You could alternatively get a PCI SATA controller and use SATA drives. Have you thought about that?