I say "well" too often. Well, sometimes I use it to buy time while I think of what I'm gonna say. Or I'll drag it out before stating my opinion that's probably opposite what's wanted. ( "Well, I think you know what the truth is, but you don't want to admit it.").
The phrase that makes me want to grind my teeth to bits is "at the end of the day." Especially when I hear it at the beginning of the day!