Re: Can't decide on case
As already mentioned it's pretty much personal preference. For instance, the case isn't particularly important to me, I put the computer together and once it's running I stick it under the desk and forget about it so I don't really care about lights and windows and other purely visual aspects.
Most cases should be able to provide adequate ventilation for typical builds. However, if your friend is a gamer and planning on going extreme with multiple GPUs and overclocking and such then the case will need to have above average ventilation and multiple fan mounting locations. Might also consider other things such as portability if the friend likes to attend LAN parties and such. If the computer will be constantly upgraded then consider how easy the access is to change cards, memory, etc...