Everyone's taste is so different. I've found usually what makes the most difference for me is the wood barrels used to age the wine, and how much time they spend in those barrels. The good barrels are expensive, so the wines are usually more expensive. My friends don't share the same taste, and I wine that I absolutely love is just not their favorite. I've also found a ton of variation in wines among bottles. I have a relatively cheap bottle I really like that is at the local grocery, and some have that great flavor that I really appreciate, and some are just blah. I've seen the same thing wine tasting, I have a wine I love and I bring the bottle home and it's sometimes not the same. I've kind of narrowed it down to spending time in the trunk of the car while I drive home in 100deg F temps. Now I bring a cooler with me to keep the wine at the cellar temp, but if you ask anyone who knows about wine they would say I'm being ridiculous. A wine fridge isn't required, a short time of the wine getting warm doesn't "damage" the wine, but I swear I can taste the difference. Maybe it's just luck, I've never A/B tested it.