I like to call the H77 the basic motherboard, use it if you are not overclocking and using crossfire/sli. The Z77 on the other hand is for computer enthusiasts who like to overclock and use multiple GPUs. So your answer is get the Z77 if you plan to use it for what it was intended for, overclocking and multiple GPU setups. So the H77 will be cheaper while the Z77 is more expensive.
The h77 is Intel's performance-mainstream chipset. It supports all the z77's features except for OC and SLI/CFX, which makes it suitable for nearly 99% of people and businesses.
So, as social said, the z77 is only worth getting if you either plan to CFX/SLI or get a K-chip CPU.
Since most of my overclocking adventures on past PCs ended up with a corrupt OS, I gave up on that and decided to go with a P8H77-M/CSM board and i5-3470 when I rebuilt my PC for Win8 last weekend. I'm still happy with my old HD5770 for what little gaming I do so I'm not going to need SLI any time soon either.