Opinions about Tire Sizes???

I'm curious what tire sizes are preferred. My rig has 215/65R-15's all 4. I'm not sure what the stock size was? Or how big a tire you can put under there without rubbing when turning. Info I'd like to consume prior to purchasing my next set. Thanx.

I'm running 215/70R-15s on steel wheels at all four corners. The front tires rub near the steering limits, but it's not a problem if one pays attention.