I don't even understand how the best answer is the best answer. The answer does not explain why the i5 and i7 is good for what it is, and completely disagreeable. i5 does fine for regular usage, but i7 is better for gaming, and 4 actual cores will be better for multi-tasking.
And as for the statements vamosabesarnos made, purely outrageous. Very mistaken information. You can't compare a CPU with Ghz, and amount of cores. All the CPUs listed don't belong to an < or > chart.
Also, i7-4500U, i5-4200U, i5-5200U, and i7-5500U, has TurboBoost which boosts the CPU, when in need, to the same speeds you get on the same model number part but ending with H. And also, i5 Mobile are atrocious, because they only have 2 cores 4 threads like an i3. F****** wasted. I'd rather spend less on i3.