I had my hand slapped for replying to several on-line complements with "Aw, gee "blush-blush" so I guess I am nominating that phrase. (Although my response to the snarky comment that I was being juvenile and silly was something on the order of "I spend my whole work day working with people who are silly and juvenile...maybe it just wears off on ya after a while.")
Would also like to give support to banishing the use of "amazing" "awesome" and "incredible" for all occasions that are not amazing, awesome or incredible. (And to the young friend who said "Miss Lily, you look incredible", Sweetie, that suggests I lack credibility, not that I am looking good.
My number one pet peeve, however, is best summed up by a T-Shirt slogan on Snorgtees : "Your incorrect use of the word literally is making me figuratively insane."