I replaced all of the outside lights on a camper and our stock trailer with LEDs. I picked them all up from Wal-Mart. Pretty cheap and work well. They are bright suckers. Only issue I've had has been on the stock trailer. The lights I bought will snap right into the existing holder that the factory incandescents did and plugged into the same harness and everything. Now the original factory screws are starting to rust and I've lost ground on one and fixed it, now I have another starting to act up the same way. I would run dedicated ground wires, but that isn't easy with a stock trailer when all of the wiring is run inside of the structure of the trailer to keep animals from tearing it out.
I saw the older camper the other day, the lights are still on it and looked good. I installed those in '07. The lights on the stock trailer were installed in early 2010 and just as bright as ever. My utility trailer also has LED lights and have had no issue with those. Just wish the new camper would have come with LED lights.