In my numerous wine reviews, I have been using a rating system that the Real World Winers developed for our original blog. It is a rather simple system with three basic rating categories. These are: Drink & Buy, Drink Not Buy, and No Drink No Buy.
Drink & Buy: These are wines that I enjoy drinking and consider worth their cost. These are the wines I would recommend to others. Within this rating, there is also a special subcategory, the Value wines. These are wines that I consider to be worth more than their cost, and thus are a very good value. Such value wines generally cost $25 or less.
Drink Not Buy: These are ordinary wines that I could drink but generally would not buy myself. I don't consider them worth their price. I would drink them at a function, or if someone else was buying. But I would save my own money for wines in the first category.
No Drink No Buy: These are wines I would not even drink if they were free. I would not recommend these wines to anyone!
As you can see, it is very simple. And that probably won't change as I don't see that I need anything more complex.