|Grasshopper posted a good link but it's been updated for March. The latest is posted below. Pay attention to this statement in the article:|
"This list is for gamers who want to get the most for their money. If you don’t play games, then the cards on this list are more expensive than what you really need. We've added a reference page at the end of the column covering integrated graphics processors, which is likely more apropos."
Best Graphics Cards For The Money: March 2010
Here's the list that was referred to in that statement:
Graphics Card Hierarchy Chart
That being said, kuwese made a great recommendation in the Radeon HD 5450. Since you're not a gamer, I don't see why you'd need anything more powerful. And if you can find one that's passively cooled (no fan), it will be completely silent.
Passively cooled Radeon HD 5450's at newegg.com