P8Z68-V PRO/GEN3
Intel 3rd Generation Core i5-3570K CPU
Asus nVIDIA GeForce GTX 550 Ti Graphics Card

I currently have this 3 components in my computer,
i would like to upgrade my computer so that i am able to play Battlefield 4 on max settings and GTA V early next year. I currently have no idea where to start looking for possible upgrades. If possible i would like to use the same motherboard.

i'm sorry if my english confuses you, and i would really appreciate any opinion you give me. Thanks in advance!What's your budget?
What power supply do you have, make & model?
And, what resolution do you play at?
All you'll really need is a graphics card upgrade, assuming you have a decent about of RAM already. Quote from: Calum on October 13, 2013, 10:52:13 AM

What's your budget?
What power supply do you have, make & model?
And, what resolution do you play at?
All you'll really need is a graphics card upgrade, assuming you have a decent about of RAM already.

Alright, you should be good to go with just a graphics card upgrade then.  What's your budget?

In that case, pick up either an AMD 7970 for £200-250, an R9 280 for around the same price (also the same card so just pick whichever is cheapest) or on the Nvidia side, a GTX 680 or GTX 770 (also the same card) for a little more, around £250-280.

All are excellent choices and will last you well, I would go for the AMD 7970 as it's the better bang for buck right now.

Indeed, it's definitely the best value for money card with the prices at the minute.

You would be best off uninstalling the Nvidia drivers and software before installing the 7970 - you can use this tool (DDU) to do that.

The procedure would be: download latest AMD drivers and save to desktop or somewhere accessible -> run the DDU tool, check all three boxes, and choose the bottom option on the left -> DDU will uninstall Nvidia drivers and software and shut down the PC -> swap the cards over, physically -> boot the PC up -> install the AMD drivers you downloaded earlier -> reboot -> game on!

I would get this one instead.
http://www.overclockers.co.uk/showproduct.php?prodid=GX-293-AS&groupid=701&catid=56&subcat=938

Cheaper, and one of the most highly regarded 7970s on the market - plus, free shipping, and free game codes, I know the cards on Amazon come with free shipping but not sure about the codes.

Sure, depends what exactly you like in a case in terms of looks, but have a look at the Bitfenix Ronin or Shinobi, Coolermaster CM 690, possibly the HAF 912...if none of those catch your fancy, let me know what you like aesthetically and I'll recommend some others

Ah, we have entirely opposite taste in cases then the Ronin is my go-to recommendation for a budget/midrange case at the minute as it's built well, looks good (to me anyway) and has the features that most people want.
You'll struggle to find a case with built in LEDs on the side panel other than very cheap tat covered in LEDs like a Christmas tree and made from recycled tin cans.  I can't think of any decent cases with that feature, anyway.
If you want the side panel lit up, you can buy LED strips which are usually powered off Molex, if those would be of use?  Then you can position it however you like to light up the case interior and your components.  Alternatively, consider some LED fans, which will help light the case up.