The first time I read "Ringworld" was when I was in high school and I still own it and have read it, along with the rest of the series, several times. It is definitely that enthralling! I have placed it alongside other works of this type such as "Cryptonomicon", "Snow Crash", "Neuromancer", "Foundation", "Darkeye: Cyber Hunter", etc. Each as intriguing and gripping in their own rights.