If you look at it sideways, an old bottle lying around under your bed or in your garage is an adventure waiting to happen. Yet when you view it upright, it's probably a tragedy waiting to happen in your glass. That's why proper storage isn't just a topic for pedants to dicker about; it's a reality. You don't need an ascot to recognize foul juice.
Properly aged wine is a true boon to the bon vivant looking to score an engaging evening doused in conversation, fine food and, perhaps, romance. Your audience is key. Just as you don't generally drape your chitchat with 5-syllable prose at the PTA meeting, it's not the wisest move to pull out the '84 Dagueneau for pizza party guests who don't have experience with a wine bottled before last Easter.
Not that there's anything wrong with the "fresh stuff" (thank you, Navin Johnson). There's no one answer to what wine is good or great. In fact, when a guest asks you, "What do you recommend?", remember that you're not the sommelier at Chez Nouveau Riche, and you're likely not a mind reader. A great reply, if you have more than a couple of options to offer, might be, "What do you like?" From there, let the hot air flow!
A great bottle of wine may be one that has a story you enjoy telling or envokes a specific memory. Was it the wine you were sipping when you had a revelation that would one day change the way we see fossil fuels? That could be as white as the driven snow and pair surprisingly well with chocolate cream pie - if your story is great. You might have a split of '92 Harlan you've store in a gunnysack, tucked between the gardening tools in your aluminum shed in Tucson. That wine? Not so sure a story can save cooked plums drizzled over asphalt remoullade. But hey.
No matter what your situation, the way to impress someone with a bottle of wine is, ultimately, to take a logical approach. Don't spoon 6-year old yogurt to a hungry child. Make it count; have fun. Only buy wines from reputable sources - properly stored, made well, road tested by a professional.