Syphon Filter®, released in 1999 on the PlayStation®, was one of the first stealth action games and helped create a new genre of video games.  You can now download the original game through the PlayStation Network and play it on your PSP.  Syphon Filter® 2 and Syphon Filter® 3 were highly successful titles on the PlayStation® and continued to evolve the adventures of Gabe Logan and Lian Xing. Syphon Filter®: The Omega Strain was one of the first games on the PS2 to focus exclusively on four-player co-op and infrastructure online play.

Syphon Filter®: Dark Mirror, IGN's 2006 PSP Game of the Year, and Syphon Filter®: Logan's Shadow, IGN's 2007 PSP Game of the Year, defined stealth action on the PlayStation® Portable. Syphon Filter®: Combat Ops -- complete with an editor that allows players to modify and upload their own maps -- is one of the first original online multiplayer games available exclusively for download on the PlayStation® Store.

Syphon Filter®: Dark Mirror PS2.  And Syphon Filter®: Logan's Shadow PS2.