Intel i3 or i5

If you're on a budget, go for i3. But if you can shell some extra bucks, go for the i5. it's worth all the money you invest. Can do some nice gaming with a good GPU too.

i3 has just 2 cores, i5 has 4 cores. The i3 is not enough to play games

In any case, core i5 is better than core i3. More robust, it can boosted at a certain level.