What one person considers a good server/channel/network others wont like. Theres more than one reason for unable to connect error. Are you typing the command to join a server correctly? When you open mIRC, close the mIRC Options, and in the main mIRC window (which says status at the top), type it like these examples:
/server irc.dal.net
/server b0rk.uk.quakenet.org
