3rd power AC power adapters?

[sremick]

I was thinking about picking up a spare "travel" AC power adapter so that I can just unplug my Wii and run without having to disconnect any of my cables (I already have a spare A/V cable, and I'd also get another sensor bar).

I see lots of 3rd-party brands on eBay and such. I am wondering what ones people would consider "good" and/or what brands to avoid...? Any experiences/opinions?