Ipad? Ipod? Mac? Hp? Dell?

Okay so I need a new computer because my tosiba computer is windows vista and and can be very sluggish at times and isn't the best computer..just trust me. I am debating if maybe I should get a ipad because i mean it is light weight and looks fun to use! haha just saying. But my brother has a Mac and I love it...but I mean it is like 1000 dollars and considering I am gonna have to buy this myself that would take forever to save up for...So I am looking for a computer in the price range like under 500...Know any good computers or ideas for me? Thanks! :)