The most reliable machine in my collection is a Gtb Wedgehead - Jacks Open.  Did my head in getting it fully working many years ago but with the help of forum members, we got it going and it hasn't let me down since.  I have thought about selling the Jacks Open but I still like the idea of having an EM in the collection.  Not to mention the divine smell inside the cabinet, love every time I open the coin door.