Hello and welcome to Tom's Hardware Forums. I suggest you edit out your e-mail address in case it gets sold to the idiots who ship out Spam.
Your VGA or video graphics adapter, is the piece of hardware that displays the images on the screen. The choice is yours on how much you spend and also depends on the slot type you have available.
What do you mainly use your computer for? There will be better advice on the Games sub-Forum if you have specific requirements.