If your are buying a new CPU then you could save a bit of coin if you do not think you will be using heavily multi-threaded work loads by going with the i3 4130 or 4330 they are pretty cheap compared to a most Ivy Bridge i5s though some might be only about $50 less than an i5. If your are not a power user and like fast and responsive browsing and steaming media as well as light gaming, an i3 4330 is an excellent choice. Though i am quite sure it can handle most new games quite well with the right graphics card. As for the latter a i5 3570K is great for a power user and depending on how close you are to a microcenter you may find one pretty cheap.