The commonly touted "best" experiences are when you just get told "wow, this code is amazing!"

I hate those code reviews.

The best ones are the ones where I get my code completely ripped apart by 10 different people in 10 different ways. Some of them might be amazing. Some of them might be arseholes thinking slating other people's code is how you climb the career ladder. But they all generally teach me something, and they all cause me to stop and think "hmm, have they got a point, or is my original design better?" The discussion that comes from those reviews is also often very interesting; and (when done well) the whole process can become somewhat of a teambuilding exercise for everyone involved.