I've actually been using my George Foreman grill and depending on the thickness of the cut...I only leave it on 3-4 minutes max. Not sure what you could use for a marinade other than vinegar?!
I actually started baking my chicken because of that. I dip it in the allowed tblspn of ff milk coat it in crushed melba toast and cook it at 400 degrees for about 20-30 minutes (guessing because I always make 6 pieces at a time for the family and for myself to save for a later date) It comes our really good. You can also boil it in sf chicken stock.
I also use the George Foreman. A time or two I've place the chicken in foil with a little bit of water and then baked in the oven. I made the foil loose but sealed so it sort of steamed as it cooked. It worked - wasn't dry at all!
I love to marinade my chicken in lemon juice and then add spices. I do a southwest marinade by adding garlic powder, chili powder, cumin, and a bit of oregano. I also like doing an Italian marinade by adding garlic, basil, oregano, rosemary, etc. Then you can either cook it on the grill (just until done) or cook in a cast iron skillet or non-stick skillet on the stove top. Also, I take a saucepan and put in about 3/4 or 1 inch of water. To the water I add salt and a bunch of seasonings like garlic and curry powder or garlic and a salt free seasoning blend. Bring it to a simmer and then add your chicken pieces. Cover and cook for a few minutes on one side, flip, and finish. I usually try to do several pieces of chicken at once when I have a flavorful water mix going and then I bag up the extra portions and freeze for easy meals later on. Hope that helps! :)
I boil my chicken and it's always moist. I then cut it into chunks or even shred it a bit. I add a mock gravy which consists of homemade chicken broth and my wasa/melba toast (finely ground) and spices. It has a great 'comfort' food taste. It's quickly become a favorite :)