Nothing transports me to another time and place as well as music that I used to listen to. I regularly listen to music that I listened to during a great period in my life, and my spirits are instantly lifted up. Some specific smells are vividly but at the same time very vaguely nostalgic to me. I feel it intensely, but I don't know why and can't connect it with a certain time period.
Of course, old video games and the 90s in particular are incredibly nostalgic to me. But I encounter it often, so it doesn't really hit me as hard as those sudden punches of nostalgia that makes you remember things you thought you had forgotten forever.