I have a whole bunch of externals and would recommend any of them:
- LaCie Rugged. These are what the genius bar at the Apple Store uses, that's gotta say something right?

Not the most "sleek" looking but the rubber shock protector makes me feel more comfortable travelling with it or throwing it in my bag.
- G-Tech Mini. I like the look of the drive a lot, but the one I have is slightly off-balance which drives me crazy. Don't know how pervasive of a problem that is. There is a bright white light on the front that is always on and flickers when the drive is being accessed. It doesn't bother me too much, but other people might be more sensitive. Though I have no complaints about the performance of this particular drive, I do have another external G-Tech (2 TB) that has given me a lot of problems with ejecting it.
- OWC enclosures with separately purchased HDD. I love the look of these enclosures (they're clear, so you can see exactly what drive is in them), and you can swap disks in and out if you want to upgrade or a drive fails or something. There's a bright blue light on the front which does bother me, more than the light on the G-Tech at least.
I also have some enclosures from MacAlly that have served me well. They're very compact. As long as you have multiple backups and the drive you decide on has a warranty, I wouldn't worry *too* much about other people's anecdotal experience. All drives are capable of failing.