Kyoto is a city of incredible history and awesome architecture. If I could recommend only one sight in Kyoto, I would choose Kinkaku-ji. Kyoto's Golden Pavilion is a masterpiece. It's coated in gold leaf and surrounded by a reflecting pond and green forest.
I recommend stopping by the tea garden on the path from Kinkaku-ji.
To get to Kinkaku-ji, catch a bus from Kyoto Station. It's about a 50-minute ride.