graphics card?

I have never had a graphics card but am wanting to get one. I have looked at some of the discussions on here but they never end in agreement. Could you help me find the best card for the $150 and under price range. I don't mind ebay.

Thanks

Do you know if your motherboard uses AGP or PCI-Express for the graphics card? Also, do you know what graphics card you have now, or are you using on-board graphics (where the graphics card is actually built into the motherboard)