The best trans drain plug you can put in is one you make yourself. I looked for a good spot to put one (inside clearance), then I bought a 1/2-20 nut and a 1/2-20 oil pan plug at the parts store. Drill a 1/2 inch hole in the pan, tighten the nut onto the bolt through the hole in the pan. (Nut on the inside, bolt head on the outside). I weld but it shouldnt cost more than $5 or a cold beverage to get someone to weld the nut for you. It doesnt need to be fully welded- just enough to keep it from spinning while tightening or loosening the drain plug. Make sure you buy a drain plug- not just a bolt, so you get the washer and all.
Total cost- $3 + welding and it doesnt leak a drop.