VNC Clients
I've got a PC running the Fedora Core 5 distribution of Linux. Running the Secure Shell (SSH) daemon and VNC servers on the machine turns it into a wonderful terminal-server. The distribution of VNC that I use is RealVNC, developed by a team at AT&T. I could use TightVNC, which features better compression characteristics, but I've experienced weird display behavior with it in the past and prefer RealVNC's stability.
When using my PC from work, I use the RealVNC client to access any of my RealVNC servers and always experience excellent performance. I should also mention that I always tunnel my VNC connections through a secure SSH connection. Because the VNC protocol lacks encryption, it is critical that VNC traffic be tunneled through a secure channel to shield it from snoops.
When using my Macs, I use the "Chicken of the VNC" (cotvnc) application to connect to RealVNC servers. I always see greater lag over a cotvnc client connection than a RealVNC connection. I've tried matching the encoding algorithms and display characteristics on my PC and Mac, but never see the responsiveness on the Mac that I do on the PC. I'm going to continue experiementing with VNC settings, but in the meantime the difference in performance has got me scratching my head.