Pour Rotel and corn into a fine mesh sieve separately. Press with a spoon to remove as much liquid as possible. Pat dry on paper towels if time allows. This step prevents a watery dip.
Beat softened cream cheese and sour cream together in a large bowl with a hand mixer or stir vigorously by hand until completely smooth with no lumps.
Sprinkle ranch seasoning packet over the base and stir until fully combined. Add garlic powder and black pepper. Taste before adding any extra salt — the ranch packet is already salty.
Add drained Rotel, corn, and shredded cheese. Fold together until evenly distributed. Taste and adjust — add a squeeze of lime juice if it tastes flat.
Cover and refrigerate for at least 1 hour before serving — overnight is best. Transfer to a serving bowl, stir, and surround with chips and crackers.
