I bought the BAFX ELM327 from Amazon. I can't attest as to whether it's better than the others, but it does work in my car. I have seen others post that there are some smaller versions with on/off switches.
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x = ac97968bd3df8f968c8cd3df998a9c94d3df9c8a918bd3df9c 909c94df8c8a9c949a8dd3df92908b979a8ddf998a9c949a8d d3df8b968b8cd1
x = ~x