It all depends on what your particular taste is actually. A sweet white wine, like a Piesporter, may be what you prefer. Some people, like myself, find dry red wines to be more enjoyable. In the case of Cabernet Sauvignon's, they are too dry in my opinion, I prefer Merlot's or Shiraz's to the cab's. Although a large portion of Merlots are somewhat sweet, there are some good dry ones available. Shit, I'm totally straying aren't I?
What makes a wine "good" or "great" is subjective to taste, much like anything else. For reds it can depend on the tannens in the skin of the grapes, where they were grown, how long the wine has aged, how well the fruit was harvested that particular year, and many other factors. All of those factors can also affect white wines, but I am not as familiar with whites, so I can't really comment on them
You should probably narrow down the type of wine you are trying to describe, and then ask this question again. I would stick to one of the main varieties of wine such as a Port, Merlot, Charrdoney, Zinfandel (reds are excellent!), Piesporter, Pino Noir, and so on. It will probably make it easier for someone with the appropriate knowledge to answer your question

Stay away from more obscure wines like Ice wine and Tuscan reds, as information is not as readily available.
Sorry this was not exactly the answer you wanted, but I hope it helps
Q-