Yeah I would agree, World Gym in Worthington is probably the best. Plenty of free weight equipment, and last time I was there, it doesn't seem to get too crowded. Although with the new year's resolution crowd, that may have changed temporarily.
There are a handful of well-known bodybuilders, powerlifters, and fitness competitors that Ive seen there on a regular basis. Not that it makes a big difference, but it's kinda cool.
The World Gym in Hilliard is a little newer - might be worth considering depending on what part of town you live in.
However, I must admit that I currently go to Lifestyle Family Fitness (formerly California Fitness) - far from hardcore, but I'm paying only $9/month, and their locations are better for me. Gets the job done, good variety of equipment - they just need more squat racks!