The Wertzone: The Longest SFF Novels of All Time
A well-researched list of the longest SFF novels and series. The decision not to include Discworld as a notable series is unforgivable. Also surprised Honor Harrington was not on the list.
If you are looking for something to read this is a pretty good reference for some ideas. The nice thing about getting into a long series is that if you like the first book or two you know you have so much to look forward to.