CPU
GPU (If not integrated into CPU, for gaming a discrete GPU is highly recommended)
RAM
Motherboard
HDD
Case
PSU
ODD (Optional)

Thank you! Is it possible to buy a motherboard already with the processor, say i5, on, with the fan etc, and it fit into any case? Then just buy the rest of the stuff like you mentioned separately? Also does the psu come fitting in the case already? Thanks for your help!

I do dont think there are any motherboards like that. And you have to buy a power supply that fits into the case they do not come with the case. atleast thats what i think. Im no expert on cases. i dont know whether they do or not. Maybe they might but they are probably not good brands.

You can get certain bundles on websites such as Dabs (depending where you're from of course) where they put the CPU and heatsink onto the motherboard and send it to you.

You do get cases with PSU's already mounted as well. They just tend to not be very good.

Ahh, there's no chance I'm gonna be ale to build this -.- What if I get the wrong bloody case and my motherboard won't fit or my psu? :L

You'll have absolutely no problems with the TTG PC Section at hand. I'll help you tomorrow if someone else hasn't already.

Okay thank you! I understand every component pretty much, I'm just not good with motherbaords and I don't know which one I need at all and which ones are good for what I want out of my pc Thank you again for your help!