Too many gamer's tuck the PC case back in under benches and other places to make things look neat , without realising that by doing so they greatly reduce the airflow available to and through the case.

Use the BIGGEST case you can and DON'T have a birds nest of spaghetti in the wiring as this reduces airflow as well. 

Plenty of fans too helps  not to extract but to push cool Air in, so a large volume of Air through the case at low speed is much more efficient at cooling that high speed lower volume.
Low speed Air picks up and carries more heat out than high speed as it is in contact with the heat sinks longer thus removing more heat as a result.
my PC runs at about 30-60 Deg depending on the Load I use a H80 Water cooler on the CPU and 4 large fans pushing a lot of Air through the case at a relatively low speed.

What like this you mean  

Small one