I make a point of trying as many donuts from as many donut shops as I come across. There are some great ones here in the bay, like
Dynamo and the more classic Bob's, but time and time again I keep coming back to Krispy Kreme.
To me they have the perfect formula. I love every single one of their donuts, their coffee is serviceable (a compliment for a donut shop from a coffee snob like me), they are affordable and damn near everywhere. Well except berkeley and downtown SF... sigh.
Now, I am saying this having never tried Tim Hortons or Dunkin, two really popular chains that I just never happened to live near or travel near
But I look forward to comparing someday.
I keep a lot of donut shops on my Yelp to-do bookmark list. This weekend I intend to try
King Ping Donuts, I'm reading that it's really popular around campus.