Usage of monitor

Hi,

I am having HP Compaq dc 5800 for my personal use with window vista / intel core 2 Duo/ 160 GB 7200 HDD/ DVD RW CD RW LightScribe and intel GMS 3100 GPU, due to some reason my monitor is not working. 

could you please advice me what is resolution of monitors  is best to buy because lot monitor  in the market.

Hope to hear from  you,

Thanks,

Carounagrane