Is Saints Row (2006) Only on Xbox 360? No — It Launched on Three Platforms

No. The original Saints Row (2006) launched on three platforms simultaneously:

• Xbox 360 (lead platform, best performance)
• PlayStation 3 (ported, slightly worse framerate, same content)
• Microsoft Windows (port by CD Projekt, 2007 — Games for Windows Live, moddable)

It was never on PS2, Wii, or original Xbox. The PS3 version is the only other console version.