What a kick! There isn't much I would say I "loathe"--more like I can appreciate that others like it, but it's not something that floats my boat or gives me the vapors in the way that things I adore do.
Lots of white space
6x6" patterned papers (pretty much all of it by every company that's putting it out!)
Polka Dots in all sizes
Classic shapes and lines
Sketched illustration work
Wood mounts (what can I say, I'm old school)
...and the list could go on for miles and miles, cuz I like so many different things.
Sap (as in drippy/sappy drivel kinda sentiments)