What is your favorite thing to marinate pork tenderloin in?!

Soy sauce
olive oil
ginger (ground or fresh)
garlic (power or fresh)
orange zest
brown sugar
ground pepper

I mix all of the above in a plastic bag, wash the pork and put it in the marinade for at least 3 days (my preference). When I'm ready to cook it I use some of the marinade so the marinade reduces and makes a nice glaze to serve with the meat. I have cubed up the tenderloin and cooked in on the stove. I also make a cavity through the meat with a knife and stuff it with whatever you like and bake it in the oven basting with the marinade that is cooking with the meat.

Lemon, herbs, garlic & mustard:

1 lemon, zest grated
3/4 cup freshly squeezed lemon juice (4 to 6 lemons)
olive oil
2 tablespoons minced garlic (6 cloves)
1 1/2 tablespoons minced fresh rosemary leaves
1 tablespoon chopped fresh thyme leaves
2 teaspoons Dijon mustard
Kosher salt
Freshly ground black pepper

Combine the lemon zest, lemon juice, 1/2 cup olive oil, garlic, rosemary, thyme, mustard, and 2 teaspoons salt in a sturdy 1-gallon resealable plastic bag. Add the pork tenderloins and turn to coat with the marinade. Squeeze out the air and seal the bag. Marinate the pork in the refrigerator for at least 3 hours but preferably overnight

Paprika pork tenderloin
Ingredients:
?1 cup chopped onion
?2 tablespoons vegetable oil
?1 to 1 1/2 pound pork tenderloin, coarsely chopped
?1/2 teaspoon chili powder
?2 cloves garlic, minced
?1 1/2 teaspoons paprika, sweet Hungarian
?1 tablespoon flour
?1 cup chicken broth
?3 medium tomatoes, chopped, or 1 can (14.5 ounces) tomatoes, diced
?1 tablespoon tomato paste
?1 red bell pepper, chopped
?1/2 cup sour cream or plain yogurt
?salt and pepper, to taste

http://southernfood.about.com/od/porktenderloin/r/bl80322a.htm

This is such a simple marinade, but it's so tasty. I usually just mix soy sauce, garlic powder, honey, sake and a touch of sesame oil together for an asian marinade. I let the pork sit in the marinade for 20 minutes or so and then cook it in a cast iron skillet and finish it in the oven. It's great to serve it with salad or an asian slaw. As with all pork tenderloins, just made sure you don't overcook it.

Sesame oil, soy sauce, garlic, coriander, salt, pepper, ginger and wasabi powder. It's great!

Marinate it in the sauce, then fill the tenderloin roll with the sauce and stich it together with cotton string. I smoke it 5-6 hours over pecan sticks in a water smoker, but the oven or a gas grill (preferably with smoke chip tray!) would be fine.
Butter, onions, 2 cups chopped pecans, 1.5 cups real maple syrup, 1/2 cup catsup, cider vinegar, lemon juice, olive oil, lemon zest, tabasco, parsley, chives, shallots.
I adapted the recipe quite a bit, and made many changes to the quantities. I don’t really measure when i make it, except the measurements listed. Saute’ the onions and shallots in the butter before making the sauce.
The original recipe I adapted it from is in the book listed below....a great book to pick up, if you can find it.