Are you referring to Firewire HDs in particular? Given the manufacturers I'd assume you are. I haven't actually owned a firewire external HD yet, but I'd probably say LaCie, mainly because they've actually been making external hard drives for many years now (don't know about Freecom, but Maxtor and Iomega are pretty new to it). I do have a Que! Firedrive CD burner, which is nicely put together, don't know offhand if they make HDs though. You may want to check some Mac publications/web sites since that's where most of these drives get used.
If you mean internal drives though, I've been *very* pleased with every Seagate Barracuda IV (EIDE) that I've used.
Another possibility is to get a firewire enclosure for about $100 and then get whatever IDE drive you want to put in it.