There are no things you should say to a Filipino. If you're using them as insults, just be warned that we'll get offended, and from there, it will be like water under the bridge in terms of reconciliation.
If there's one thing I've learned about Filipinos is that they tend to come back fighting with more life left among their bones than what they started with. Insults may hurt on the inside, but when Filipinos encounter such feedback, their face becomes surprisingly motionless, and we often consider our words before acting (or not). The sentiment comes from old wisdom passed down through generations, saying that all people deserve respect no matter how much disdain is thrown at them. It's said this action speaks louder than words, and this is one of the many traits we Filipinos are proud to show.
So if you're going to say something nasty about a Filipino, may I suggest reconsidering (but only once)? Remember: even if you're only joking around in good faith (because honestly, commenting on a person's race IS offensive), your choice of words will still reflect what you think about us. I know it's a difficult thing to reverse, but all the same, try and drop that habit.
Filipinos are friendly people if you give them a chance to be if you can't appreciate our culture, at least respect our right to have one. We're known for being loudmouthed and wacky, but when it comes down to it, we're not the worst race you'll ever encounter in your lifetime.
Think before you speak. Think again. And think some more before opening your mouth- something that's become a necessity because we tend to be loudmouthed and witty with words. Our heritage of wisdom is there to defend us, just like how our culture has supported us through the years.
As I conclude this message, I close in with a powerful Filipino proverb: "It's better to keep your mouth shut and appear stupid than open it and remove all doubt."