Best $100 or under passively cooled DX9 card:
1) Radeon 9600 ($85)
2) Radeon 9550 128-bit ($65)
Radeon 9600 pro for about $105+ would be a better performing gaming card than these two, but is not passively cooled like the two above. I should add, that while this may look like I only support ATI, that is not the case. Nvidia just doesn't have any DX9 AGP cards that compete with their ATI competition until you get well above this price range.