And, don't forget, if you're at a restaurant, and want a wine by the glass, you can always ask for a taste first. (Solves that Pinot Noir doubt--you're so right, while many are good, there are some horrible ones out there, too!).
When I was a waitress, and someone was torn between the wines we were pouring by the glass, I'd suggest that they get a taste to make sure they liked it. With glasses of wine costing $7.00 and up a pop, it's the least a restaurant can do.