Best tape / cassette to mp3 usb converter?

You may not need to buy anything. If there is a headphone socket on your cassette player then it's easy. You will need a cable with a stereo jack plug (3.5mm) at each end. You will also need a recording programme, I use audiograbber which is a free download. Then plug the cable into the headphone socket on the tape, and the line in socket behind your computer. Start Audograbber and under file select line in sampling. Start off with the tape volume fairly low and adjust till the recording levels are OK just to test. Then simply record to your computer. If you wish to convert to MP3 you will need an encoder, the instructions for downloading this are in Audiograbber. Hope this helps.