I just finished this for the umpteeth time over the weekend. Wait. Let's quantify that. It came out in about 1985 so it's around 35 years old; say I read it every 3 years. Okay, I finished reading it for approximately the eleventh time over the weekend.
  I don't really need to say much more. This is one of the best fantasy series I have ever read. Ten out of ten every time. The 'other world' is brilliantly envisaged and described. The plot is relentless rather than convoluted. The characters leap off the page. If you are not shivering and clutching a hot water bottle after reading the worldview descriptions, there's something wrong with you. The ending is unexpected; you guess something unexpected is going to happen but when it does happen... it's unexpected.
   There is no excuse if you are a fantasy fan. This has to be on your CV.