I really like Fox glow plugs. The RC Long is my go-to 2-stroke plug, and I really like the Miracle plug as a cost effective alternative to the O.S. F-type plug.
I just placed a Tower Hobbies order a few days ago, however, and I ordered McCoy MC-59 and MC-4C plugs instead. Both of my favorite Fox plugs were unavailable. McCoy plugs are also terrific.