I agree with many of the things ManilaTraveler says but will add a couple of things. For Hosseins, don't bother with the one on Makati Ave. Go to the one in Serendra--much better.
For Sunday brunch, the crossover buffet at the Dusit is not to be missed. It's less than $30 per person and you get to go to 4 of their restaurants. Italian, Japanese, Thai and International. We have been known to spend a few hours there and you even get a 20% discount with a platinum Amex.
We used to go to Museum Cafe for Sunday brunch but they changed their beef from Wagyu to ribeye and cut out some of the other food so we found Dusit. Glad we did.
There's so much there that it will take a few times to enjoy everything.
Regarding People's Palace, have you eaten there recently? I used to think that it was the best Thai place also but we went there a little over a month ago and the food isn't as good. I've spoken with many other expats and locals who feel the same. Thai Silk in Serendra is decent but the quality has deteriorated a little also.
I'm not a big fan of New Orleans but it is decent. Clawdaddy's next door should be skipped--we've been there twice and the food was not good. However, we did not have the crab.
For Dimsum, there is a good restaurant in the Crown Plaza in Ortigas which some say is better than Hong Kong. I've only been there once and can't recall how good it was.
Another hawker center type place is at Tiendasitas. They have an outdoor one and an indoor one with the SM Hypermart.