phrases to use to pretend you're not a bad person

As promised, just a little bit late.

No offence

Usually followed up by something offensive. I've seen about 3 cases where the following statement is not offensive. And it just seemed like the person used "no offence" for no reason whatsoever.
Granted, offence is taken and not given. Hence, saying "no offence" does not stop you from giving offence. Depending on who you're talking to and what their values are, they may take offence for the most seemingly innocuous comment, or they may be happy with you making jokes about Hitler and the Jews.
That is why comedians can make the darkest of jokes and the audience still laughs - luckily only those that do not take offence came to watch the show.

I'm not a racist/sexist/etc, but...

Usually followed up by something prejudicial. A comment that is clearly inappropriate, and the person who says this is trying to pretend this is not their usual way of thinking or something.
But usually leaves a lasting impression of racism/sexism/etc, so uber duber.

Just saying

Usually followed by something that everyone else wishes was not said.
Tries to justify the existence of their stupid statement, but in the end the statement undermines its own value.
A milder form of "no offence", in that it's not guaranteed to offend (of course, it could, though, if the listener decides to take offence).

Frankly/To be honest/Not going to lie/etc

Feigns a sense of objectivity where none exists.

I hate to be a told-you-so...

Usually followed up by said person being said told-you-so.

I was being sarcastic/trolling/ironic

For those that really have no idea how those work. "Covers up" a bad joke because they've seen people use these terms to explain jokes that the perpetrator did not understand. It's really pathetic when I see this whipped out, when there is no trace of sarcasm or irony. Don't get me started on what "trolling" actually is.