Ok, sorry for apparently offending you. To be fair, your post title is misleading. You say you need help building, but you don't want help building, you just want help choosing something to buy that is already built. You will be doing no building, despite the title of your thread.
Here is a decent pre-built in your price range.
http://www.ibuypower.com/Store/Revolt-2-Special
If you really do not want to build yourself and do not want to know how badly you are getting screwed when buying a pre-built like this, ---STOP READING--- and buy it. It's decent enough and will play games ok.
cons to getting this:
unusual case that to change costs a lot more than it should
GPU is only a GTX950, with a custom build for $1200 you should be getting a
lot more powerful than that
You have no clue what brand that PSU is going to be and it could fail shortly after warranty is out as they tend to cut corners here and go cheap. Pretty much all pre-builts do this though so not much you can do about it.
120GB Kingston SSD. With a $1200 budget, you should easily be able to fit a 250GB from a more reputable manufacturer.
No clue on the HDD manufacturer. Similar to PSU, these types of site just go with what is cheapest. Cheaper ones don't last.
With just a little bit of work you can get this for about $30 more but still within budget:
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i5-6600K 3.5GHz Quad-Core Processor ($253.99 @ Amazon)
CPU Cooler: be quiet! Dark Rock 3 67.8 CFM Fluid Dynamic Bearing CPU Cooler ($63.99 @ NCIX US)
Motherboard: Gigabyte GA-Z170-HD3P ATX LGA1151 Motherboard ($89.99 @ Micro Center)
Memory: Corsair Vengeance LPX 8GB (1 x 8GB) DDR4-2666 Memory ($50.99 @ Amazon)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive ($84.98 @ OutletPC)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($48.88 @ OutletPC)
Video Card: Asus Radeon R9 390X 8GB Video Card ($359.99 @ NCIX US)
Case: Corsair 200R ATX Mid Tower Case ($49.99 @ Micro Center)
Power Supply: EVGA SuperNOVA GS 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($69.99 @ NCIX US)
Operating System: Microsoft Windows 10 Home OEM (64-bit) ($99.98 @ OutletPC)
Total: $1172.77
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-01-28 23:03 EST-0500
Better cooler.
Better brand and larger SSD.
Known to be excellent quality HDD.
MUCH better GPU. You could push 1440p with that thing instead of struggling with 1080p. We're talking playing games on Ultra here. Don't have to worry about turning settings down to make a game playable.
Known good quality PSU.
If that is still too much for you to handle I would recommend lowering the GPU slightly to stay within budget, still purchase the parts individually yourself and taking them to a local computer shop and paying them to assemble it for you. Should cost about $100.
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i5-6600K 3.5GHz Quad-Core Processor ($253.99 @ Amazon)
CPU Cooler: be quiet! Dark Rock 3 67.8 CFM Fluid Dynamic Bearing CPU Cooler ($63.99 @ NCIX US)
Motherboard: Gigabyte GA-Z170-HD3P ATX LGA1151 Motherboard ($89.99 @ Micro Center)
Memory: Corsair Vengeance LPX 8GB (1 x 8GB) DDR4-2666 Memory ($50.99 @ Amazon)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive ($84.98 @ OutletPC)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($48.88 @ OutletPC)
Video Card: Asus Radeon R9 380X 4GB Video Card ($238.98 @ Newegg)
Case: Corsair 200R ATX Mid Tower Case ($49.99 @ Micro Center)
Power Supply: EVGA SuperNOVA GS 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($69.99 @ NCIX US)
Operating System: Microsoft Windows 10 Home OEM (64-bit) ($99.98 @ OutletPC)
Total: $1051.76
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-01-28 23:12 EST-0500