I've tried Hershey's 60% and Lindt 70% and 85%.
The Hershey's, in retrospect after tasting the Lindts, isn't very "exciting" but on the other hand it seems a decent way to wet your feet.
Next try was the Lindt 70% which I really, really liked. It has a lot of acidity to it. My dad said it had a tang like "green raspberries."
I'm working on a bar of Lindt 85% now. At first I wasn't too thrilled. Obviously at 85% bean it's very very strong. But then last night I switched back to the 70% and I missed the strong roasted flavors of the 85!
Overall, though, I do think the Lindt 70% is very tasty and goes down easy.
Next in the cupboard is a Ghirardelli 72%. By the way, I get the 3.5 oz. bars on sale; 2 squares is usually nearly exactly 100 calories (the Hershey's was a bit different I think), so I break it up and package 2 squares at a time in foil, so it's all ready to go!
Unfortunately, I live in the boonies. Even Trader Joe's is an 80 minute ride one way (though a friend and I have been known to make the trip

). So while I'm generally stuck with what I can find at the local grocery or Walgreens, we're lucky that even those stores tend to carry at least Lindt and Ghirardelli.