I recently got a new computer, and I'm taking this time to finally clean everything and get rid of that custom content I always skip over and never use anyway. I know it will make my game run quicker, and it's time. I have Delphy's organizer, and I know how to search through bad files, getting rid of the custom content I don't want, and all that good stuff.
My question is: with SO much CC, are there certain files that are notoriously bigger or more of a problem than others? I have too much of everything, but I don't know if, for example, getting rid of CC hairstyles makes a bigger impact than getting rid of CC floors. I just thought I could concentrate on a certain area to begin the weeding out. Thanks!

The best way to find bigger files is to scan the folders using Treesize Free: http://www.jam-software.com/freeware/

Have a go at compressorizing your files too. Sometimes it doesn't make much difference. And sometimes it's magic.