You've got Suse listed in your distributions, so I'm surprised you don't already know about the "Knights" program. It's part of KDE, but I'm not sure which other distros include it, but I know it's there on Suse.
Knights is just a gui front end - requires a chess engine; Suse provides Crafty for it (or Phalanx in Suse 9.1), which plays a pretty good game (I play club level, and I struggle to beat it).
It's got multiple scalable graphical themes, and can also connect to various internet chess servers, so yes, I'd say it's a pretty good program.
I'm not a heavy Gnome user, so I can't vouch for any Gnome equivalent, but I'd be very surprised if there wasn't one.