Upgrading Pc need help

This is what I'm currently runing

PCPartPicker part list: http://pcpartpicker.com/p/VkscVn

CPU: Intel Core i3-2100 3.1GHz Dual-Core Processor

Motherboard: Asus P8H61-M LX  Micro ATX LGA1155 Motherboard 

Memory: Kingston 4GB (1 x 4GB) DDR3-1333 Memory 

Memory: Kingston 4GB (1 x 4GB) DDR3-1333 Memory  

Storage: Seagate Pipeline HD 1TB 3.5" 5900RPM Internal Hard Drive

Video Card: Zotac GeForce GTX 770 2GB Video Card  

Case: NZXT Beta Evo ATX Mid Tower Case

Power Supply: Corsair Builder 600W 80+ Bronze Certified ATX Power Supply

Operating System: Microsoft Windows 8.1 Pro - 64-bit (OEM) (64-bit)

I recently purchased an Adata SP910 256 gb

I'm think of upgrading the the cpu, motherboard, ram and keep the rest the same if possible but I have no clue what I should even be upgrading to, should I go for amd or upgrade to a newer intel

I'm don't really overclock  as for budget not more than $400

I mostly use the pc for gaming but some times use illustrator Photoshop and even do some light video editing

As for games I mostly play FPS player bf4, cs:go also some other games such as dota 2, diablo 3 and sometimes guild wars 2.

If you want to save some money, get an ivy bridge i5 and youll be fine. Higher clocked would be better, but you dont need a k part.

--> i5 3570, 3550 etc., whatever is cheap at the moment.

If you sell your i3 and buy an i5 on ebay youll pay about 50-70$ for your upgrade.

For Gaming:

You dont need more ram

You dont need a better mobo (except of course you want do do something your current mobo cant do)

You dont need more than a proper quadcore cpu.

 

You could use a better CPU and more ram for faster video rendering and Photoshop, but if you just do that on the side its not really worth it (besides, 8gb ram and an ivy bridge i5 is not bad for those applications)