Kevin Brown has a nice expository article Jewel of ArithmeticJewel of Arithmetic
and Franz Lemmermeyer has compiled a list of all published proofs
both of which are worth a look.
Edit: I just thought I'd add that there are 224 published proofs in Franz Lemmermeyer's list, and if you are using frames and if your institution subscribes to the online version of Mathematical reviews or Zentralblatt, then the reviews will appear in one of the frames.