A lot really depends on what kind of neighbors you have.
If you are sensitive to noise you might want to avoid certain brand new buildings and certain neighborhoods (i.e. CityPlace) where there are a high-number of young renters living.
In my experience, older buildings in mature neighborhoods are more likely to be owner-occupied and have long-term residents. Owners generally care about where they live and are more considerate of their neighbors than renters. I live in a 17 year old boutique condo (smaller building) with a mix of residents ranging from young couples to actual seniors. I have never had to deal with a sub-woofers, loud music, parties, or even hallway noise. Knock on wood, everyone seems very considerate and quiet.
A penthouse is a good strategy if you can afford it. However you will still likely hear some level of noise. Even if you are on the penthouse, you will hear impact noises from units beside you traveling through the floorplate into your unit. You may also have to deal with mechanical noise. But generally these are noises you should be able to get used to.