I used to be a member of the Dowd YMCA, a posh branch that definitely has its perks. But I much prefer the low-pressure Johnston. The Johnston Y reminds me of the YMCA from my childhood in Chicago. It's in a cool old building and it's not fancy. The members are friendly and diverse. And there's no competition.
The classes are great. I like yoga (especially Kundalini yoga with Patty) and zumba, where more than 50 people dance like crazy in the gym.
If you live in NoDa or Plaza Midwood, the Johnston Y is your best choice for a gym.