As the title indicates.... I'm looking for ideas where to go on my next two trips to Asia.

What I have planned (and booked tickets for) so far:

• 15 day trip, arriving in SIN on Nov 11 2012.
• 12 day trip, arriving in SIN on Jan 28 2013 (after having been in Australia for a week).

In essence I have almost 2x 2weeks starting in Singapore in November and February. I choose SIN as a staring point because it's fairly cheap to get to from Europe and has easy connections to almost everywhere else.
What I'm looking for is a mix of interesting things to do and some days at the beach. I haven't seen much in Asia except Japan/Korea/Hong Kong so those are probably of the list.

So far I have been looking at Malaysia, Bali, Bangkok and some beach destinations in Thailand, and spending a few days in Brunei. But I'm wondering what I missed by only looking at these more obvious destinations....
So I'm looking for your favorites and maybe some advice on what countries to avoid in either the two periods that I'm there in Nov/Feb due to weather or other circumstances.

Budget is flexible but I would like to keep it below €250/$300 a day excluding airfare. And I like a little luxury and some good food.

Thanks...