史記 is GREAT fun. One of the few classical books I really enjoyed reading, though to be honest I haven't read a whole lot (I've read lots of excerpts though).
There's a collection of 台灣古典散文, that's worth reading. Very interesting stuff, all little bits and pieces. A lot of it's probably more interesting for me than you because they mention a lot of places in Tainan, which I drive past everyday (or can go down and look at). There's the odd piece from Yilan or Taipei though, and a very beautiful piece about seeing Yushan from Jiayi.
Then there's this one official who ended up getting kicked out to the boonies in China (my guess is for not being corrupt enough, I forgot the official story). Anyway, turns out he was a great official but he wrote some cracked up stuff. One is a declaration to the crocodiles giving them 14 days to leave or he'll shoot them all ('I'm giving you 3 days to leave, if you haven't left in three days I"ll give you another 4, if you haven't left by then I'll give you another 7, and if you STILL haven't left I'll call all the best archers and kill you all). I'm fairly upset that I no longer have that book actually (I just remembered I lent it to a classmate the day of the exam) but the author was called 韓愈。 All of his stuff is quite good reading.
These are mostly all 散文 so relatively short (even 史記 is like a collection of short stories). haven't tried 西遊記 or 紅樓夢 yet.