“I’m sorry, but [anything].”
–Cliffy
“This is going to hurt me more than it hurts you.”
“No, that doesn’t make your ass look big at all.” 
“Sorry, that’s the smallest bill I’ve got.”
“I run a classy establishment”
‘classy’ is just one of those words where, the moment it’s used, it no longer applies.
“We come in peace”
“It’s not about the money.”
“Coming!”
I always say that to whomever is waiting for me (f.i my husband when we’re going out) when my actual intention is to be five more minutes. Applying that last bit of make-up. Or going back up to change my shoes. Straightening the cat. Whatever.
“But I did it for you.”
Or it’s for your own good, I thought it was what you wanted, etc etc
“I don’t mean to be rude, but…” guarantees that the following statement will in fact be rude.
I have a policy: People who claim that they never lie cannot be trusted at any time.
Why? Because everyone has things that they need to hide, or would just rather not tell people about. Big things, small things, doesn’t really matter. Most people, when questioned about many of these things, will lie.
Then, if they are caught in the lie, they will eventually confess and acknowlege that they have Done Wrong.
However, in my experience People Who Never Lie think that as long as they stretch the truth until it bends, or answer with a non-sequitur that seems to answer the question, or gaslight the asker till they don’t know how they feel anymore, that they are still somehow In The Right, because At Least They Didn’t Lie About It.
The fact that they deliberately responded in such a way as to cause the querent to believe something untrue is somehow irrelevant to them. They told the literal truth! It’s not their fault that the other person misinterpreted them! THEY NEVER LIE, DAMMIT! THEY HATE LIARS!!!
Etc.
We had to destroy the village to save it.
We are here to liberate you.
We will leave within 6 months.
I have a mandate from the American people to do this.
This is a temporary tax.
My people love me.
Hostory will judge me more kindly.
And,
Of course I’ll respect you in the morning.
“All models over 18.”
Actually they always are, since it isn’t worth the grief that having underage girls doing porn will bring.
My favorite is “Your call is important to us”.
"With all due respect’ isn’t exactly a lie but usually means that you don’t think that the person deserves any respect at all.
Yeah. I came in to post basically this. I have a brother-in-law like this, and he drives me bats.
“All your base are belong to us!”
Even if it’s true, you’ve just relegated yourself to geek loser-ville status by using it.
This is just a layoff; if we find need for your services, we’ll hire you back.
As panache already noted, it’s in the context of sexual acts. Every single one night stand I’ve ever picked up at a bar has said, “I’ve never done this before!” From 21 to 45. It’s so uncanny, but it’s not even surprising anymore.
“I’m a reasonable man…”
Of course, the flip side are those statements which are all too true, tho perhaps not for the reasons the speaker thinks: “Hey y’all, watch this!”