I am looking to build a pc that I wont have to upgrade to much in the future without blowing the price to performance ratio out of the water. I am fine if the cpu isn't the best since this is going to solely be a gaming rig.
Must haves are medium to high audio implementation, high to ultra graphics, high FPS, and over all quiet.
It really depends on one's experience with AIOs. I had a CM Seidon 120V($45 AIO) in my ITX build, and it worked fine despite a bit of pump noise(RMA for a replacement, atm). Nothing leaked. However, if you don't have space restrictions, I do personally prefer air coolers, which are often quieter and safer in general.