Suggest me a must-read fiction or mythological classic!

Please suggest me a classic that isn't on this list:

The LoTR trilogy

The Aeneid
The Illiad

The Odyssey

I'm looking for classics that resonate within our culture and influential works that any person should read. I'm trying to expand my literary knowledge and read a bit more but I want to start with the classics. It doesn't matter if it's hard read, I'll try, and make an effort.