What makes a wine good? I think the answer to that is different to everyone. Personally, for me the most important thing is balance. Ideally a wine should be a harmonious balance of acidity, fruit and tannin.
Acidity will help the wine age gracefully and makes it pair well with food. Too much acidity and it might be a little sharp to drink by itself. Too little acidity may mean that it just doesn't have what it needs to bring out the best in the meal that you drink it with. Personally, I tend to favor wines from cooler climates since the cooler temperatures, especially at night, maintain the grapes natural acidity and I like some acid in my wines.
While a wine needs tannin, too much can be overwhelming. A Cabernet Cauvignon with big tannins might be great with a fat juicy steak, but can be overwhelming with some other less robust foods, and might be too grippy to enjoy by itself. So, while I like a wine with tannin, I personally enjoy it's in balance with other other elements of the wine.
I like a wine that is complex, with subtle flavors of herbs and spice, but I need some fruit flavors too. Too much fruitiness can get in the way of tasting some of those other secondary flavors but without some fruitiness the wine is not enjoyable for me. And isn't that the primary purpose of wine, to be enjoyable? If you enjoy drinking the wine, it's good for you, and that's the most important thing.
If you're interested in spending some time exploring what you like in wine, consider joining one of our classes at the new wine bar in Vancouver.