I mostly use fbless ebook reader, because it works on console and don’t need to switch to X server for reading. Downside is that it recognize only .fb2 or .fb2.zip format, which is not so common. For quick conversion I use Calibre command line tool:
ebook-convert How.to.Convert.Ebooks.epub How.to.Convert.Ebooks.fb2
…quick and efficient.
Happy hacking….
How I Tamed Linux...or How Linux Tamed Me 