What is the best IM software?

I think the best IM software out there is SightSpeed Hands down the best free Internet video calls offered by any Web service. You'll be amazed at the video quality and tight synchronization of audio and video when using a broadband connection and 30-frames-per-second webcam. Phenomenal video quality. Unlimited free video calls, video e-mails (up to 1 minute with 30-day storage on the free basic account), text messaging, and voice calls to other SightSpeed users. Windows and Mac support. Low-cost calls to traditional landline phones; voice-only calling mode.