I'd say Redguard, honestly.
Despite it being one of the Elder Scrolls games, it's the least well known. In fact, most reviewers who talk about the history of Cyrodiil and all that completely gloss over the events of Redguard (Cyrus' journey from pirate, to vengeful brother, to leading a rebellion against the Empire). Maybe it's been removed from canon? I dunno.
Admittedly, it's the only Elder Scrolls where you have almost no choices and is extremely linear.
`Twas fun though. It was during that period in the late 90s when everyone was making games like Tomb Raider - 3d platformers, basically.
Another game would be Banzai!, I played on my friend's Macintosh way back when. It reminded me of Sabotage, an Apple ][c game I had. You were a little dude standing next to a mortar firing at soldiers charging your position. Tried finding it on emulators too but have had no luck. Not even a screen shot. Will check again now ...