I use IRC like many people of the Community who uses IRC for most of their text-based business, excluding e-mailing to mailing-list threads or longer pieces of text. From 2009 to April 2016, I used X-chat. X-chat was one of the programs that were removed from the main repo of Ubuntu software center. Simply because it’s not maintained anymore. I’m aware that there is Hex Chat but it doesn’t work well with my ZNC Bouncer. Nowadays I use the command-line based IRC client called Irssi.
I haven’t really messed around with the config of the client but I do have set it up to the point where it’s usable.
Like many Open Source programs, Irssi has scripts to make it more usable and I use a few of them: