I just read Twenty Thousand Leagues Under the Sea and I really liked it. I kind of got lost in the classifying sometimes, but I loved reading about all the different underwater cultures the Nautilus encountered. The ending left me wanting more. This is the first book I've read by Jules Verne... which one should I read next?
Watcher by Night
Mysterious Island is the sequel to Twenty Thousand Leagues. The two other biggies are Around the World in 80 Days (my favorite) or Journey the the Center of the Earth (which bored me no end.)