Prepare the Marinade: In a large mixing bowl, combine the minced garlic, lime juice, orange juice, apple cider vinegar, olive oil, cumin, smoked paprika, chili powder, oregano, salt, and pepper. Stir well to combine.
Marinate the Chicken: Place the chicken thighs in the bowl with the marinade, ensuring they are fully coated. Cover and refrigerate for at least 2 hours, or preferably overnight, to allow the flavors to soak into the meat.
Preheat the Grill: Preheat your grill or grill pan over medium-high heat. If using a grill, oil the grates lightly to prevent sticking.
Grill the Chicken: Place the marinated chicken thighs on the grill, skin-side down. Cook for about 5-7 minutes on each side, or until the internal temperature reaches 165°F (75°C). You can baste the chicken with the leftover marinade while grilling for extra flavor.
Serve: Once cooked, remove the chicken from the grill and let it rest for a few minutes. Serve with chopped fresh cilantro, lime wedges, and your favorite sides.