Guess it's between iterations of Saints Row, Red Faction and Summoner.

Mine's Summoner 2. It's been about decade, but I've got very fond memories of it. Guess that might change, if I take a hint and grab a copy of Saints Row : The Third one of these days.

Man - looking at that video, games from the PS1 and PS2 era really don't hold up well at all! Though there's still something to it. An interesting mix of actiony and RPG combat. It was clearly ahead of its time.

Saints Row the 2.

The original Red Faction, spent hours digging tunnels in the split screen multiplayer.

Red Faction Guerrilla I guess. I've only played the first Saints Row and it was pretty awful, so I doubt I'd like the others just because they're KRAZY.

Freespace 2.

And it's still alive through http://scp.indiegames.us/

Free space series, they need to make free space 3 and for consoles

Saints Row: The Third because it's amazing. 
 

Probably a tie between Red Faction 1 and Guerrilla. And maybe RF2 for the multiplayer.

Freespace series followed by Saints Row 3