What's the most useful or best golf training aide you've bought.

[LimitGod]

You can take it from a guy who teaches 10 lessons daily, there are good and bad training aids, however, it is necessary that once you find a good one you use it correctly.

For example, the medicus, the one that breaks down if you make an incorrect swing, I can keep that club in-tact and make a horrible move, I can also make a text-book swing and break it.

Weighted clubs are great to loosen up with but they won't do too much for your game.

I like balance disks a lot and this device called the power-angle pro. I'd post a link about what it is and how to use it but I'd probably get flamed for Spam as it's from my companies' website.