Spray chicken breasts with nonstick spray then season with salt and pepper. Grill over medium-high heat for 3-4 minutes per side, brushing the grilled side with BBQ sauce after flipping once. Grill the corn cobs, rotating occasionally, until evenly charred. Remove chicken and corn, let cool slightly, then chop chicken and slice corn kernels off cob and set aside.
In a very large bowl add lettuce (may need to do this in a couple batches). Use a pizza cutter to evenly chop lettuce into small pieces then toss with tomatoes, black beans, red onion, cheeses, desired amount of crushed tortilla chips, grilled chicken, and grilled corn. Drizzle with ranch dressing and extra bbq sauce (or your favorite dressing) then toss and serve immediately.
Notes
Use your favorite BBQ sauce, whether it's sweet or spicy.