For atx and ddr3: asrock M3A770DE $59.99 at newegg.
For micro atx and ddr3: MSI 760GM-E51
If you want usb 3.0 or sata 6.0, you'll pay at least $30 more. The above boards have alot of standard features for basic computing. Again, if you want better advice, check your case specs and see if it will take an atx board, and tell us if you will be using ddr2 or ddr3.
I will be using the antec 300 case which motherboard would be good>?