Xbox games you should have purchased back in the day, but didn't?

I had Panzer Dragoon Orta. I actually had gotten it for like $5 on clearance at Walmart. But I sold it. Don't really regret it, either, since I played it a bit and it didn't interest me enough to play more of it, much less keep it.

I don't think there are any games that I wanted for the Xbox that I don't already have, really.

@ GAMEBOY - your comment was over-dramatic and inappropriate, so I edited it out. If you don't remember what it was, you can ask me. If you do remember, please try not to make remarks like that in the future.
 
Thanks ;) I think there's only a few I wanted to try but haven't, Battle Engine Aquila, Arx Fatalis, and Jade Empire.