Tigerdude,
You're going to get just about as many answers as there are flyers. But since you asked, my solution comes from the fact that I'm cheap and don't feel like paying a lot of money to accomplish something. I buy a gallon of windshield washer fliud (around $1 at Wal-mart) and put a squirt or two of Dawn dishwashing liquid in it. The Dawn will cut the grease really well, and the windshield washer fliud will clean it all up. It doesn't streak and returns the shine to the Monokote on my planes. A gallon will usually last me all summer long.

Also, I use the blue disposable "shop rags" to clean my planes with. They are soft, but they hold up better than regular paper towels.

Hope this helps

Ken