In a large bowl, container or sturdy zipper top bag, combine the olive oil, garlic, lemon juice, vinegar, oregano, salt and pepper. Stir to combine thoroughly, add the chicken, turn to coat well, the cover or seal and refrigerate for 12 to 24 hours (or even up to 2 days!).
Preheat the oven to 425°F. Line a rimmed baking sheet with aluminum foil and spray with nonstick cooking spray. Remove the chicken from the marinade and place on the baking sheet skin side up. Roast for about 40 minutes until cooked though, depending on the size of the thighs. Serve the roasted chicken hot, warm or cold.