I'm looking for a used MacBook for my girlfriend. What's the best place (online or otherwise) to look for one?
Some resellers have used or open box items. Online places included SmallDog, MacMall/MacConnection, etc. Even Best Buy will have "open box" specials its just a matter of calling and finding the stores.
Otherwise I recommend Craigslist over eBay because you can see the computer in person.
whats your budget?
The good news is that macbooks are incredibly durable...when i bought acer laptops, which were very good btw (i'm not trying to talk bad bout em), i would need to get a new one every 2-3 years. I switched to Mac a little over 2 years ago and my macbook still runs like new...Also, no obnoxiously loud fan noise, which is one of the main reasons i'll never get a laptop that doesn't have an apple on it...
i think if were to buy a used mac i would only purchase from apple refurbished.