Anyone got a system they bought over the years that actually DOES WORK?

Years ago I purchased about 10 systems from various places over a 5 year period and I have to say, none of them are followed today. Most were advertised via Practical Punting Monthly I think including the Classcruncher and a few others. Every now and then I pull what's left out and run then through the formguide but they never take hold.

Do you have any that took hold and/or still using today?