which of these pc is best for gaming?

#2 would be slightly better, but its arguable by how much. In other words they are both very close. Although the i7 4820k is a very fast processor, the i7 4770 is just about equal and actually surpasses it in a few benchmarks. The benefit of the i7 4820k is because it is a "K" or unlocked processor and can be overclocked to boost its speed even more (there is a "K" version of the i7 4770k too though).

And more importantly, it is the graphics card that determines how well a PC can run games, and both rigs have the same card. So its a toss up. The RAM speed of 1600MHz is nice, but won't impact gaming (and you could always change the RAM anyway, its cheap).

Personally I would get the Haswell rig (#1) if I wasn't planning on overclocking, but like I said - either one is great. So go for the best deal.

And yes- I would add an SSD. Definitely!

http://cpuboss.com/cpus/Intel-Core-i7-4770-vs-Inte...

In short, the second one will be better as it is equally matched with the top one in everything except for the processor, which the second computer has the greater and faster of the two. Only plus that the 1st computer has is the SSD drive, which is always easy to add later if you get the second anyway. Also, previous comments mentioned liquid cooling, don't worry about liquid cooling, as the heatsink and fan combo that comes with the CPU should be sufficient. However, If money is a factor (1st computer seems cheaper) the 1st computer will more than easily run any PC game out today.

TLDR: The second one is better but the 1st one will work almost just as well.

The second one is better, but I recommend building your own and balancing your options out better. Judging from this is guess you are at a $1500 dollar budget which should get you all of this:

i7-4770K

Noctua NH-D14 (or H100i for watercooling)

16gb ram (4x4)

1-2tb HDD

128gb ssd

850watt psu (seasonic 80+ gold)

GTX 770/780 if you can afford it. I PERSONALLY RECOMMEND R9 290/290X

Win 7/8

peripherals if u need

if this is customizable i image pc 2 is more expensive just go pc 1 and use the extra to move to a 780 . in honesty it would yeild a way way higher performance in gaming compared to the modest cpu upgrade . games currently cannot even use the full power of a i7 proccessor . so the upgrade would yield very little .

The second one is slightly Better but i would go for the 1st one if not over clocking .

Second is better, better parts in there :)