I am arriving in Bangkok September 23’rd (very late) from California. I am staying at the Peninsula Hotel for 3-4 days. I leave from Bangkok on October 7’th. I for sure want to go to Angkor Wat, Chaing Mai, & spend some time in the south. It is our Honeymoon (we are active in our mid 40’s). I need help/suggestions in planning the rest our itinerary as well as the transportation between the various places. Thank you.

what are your interests and how long a trip are you planning? I can tell you right now that we will all tell you that you need more time in Bangkok.

I am guessing that you are spending two weeks on your honeymoon since you say you are leaving Bangkok on Oct7 (to go home?) I suggest that you spend 5-6 nights in BKK, at least 3 nights in Siem Reap (Angkor) and the remainder in either Chiang Mai or in the south. I'm not a beach person so I won't suggest say Koh Samui over Phuket (although I didn't care for Phuket), I'll defer to others who like beach areas for that. If you really must do both, then I suggest 3 nights in Chiang Mai and 2 in Hua Hin, a lovely seaside town with wonderful hotels (the Sofitel is lovely) and some beach as well.

Bangkok Air flies to Siem Reap. Within Thailand, Air Asia has very cheap flights BKK to Chiang Mai. To get to Hua Hin, it's about a 3 hour drive south of BKK. You can hire a car and driver for about $75.

Soory-- missed that Oct. 7th departure.
If that's the case I'd spend 6 days in Bangkok, 3 in Angkor and 3 or 4 in Chiang Mai. Skip the south. if you want some resort time do it in Chiang Mai at either the new mandarin or the 4 Seasons.

You want to do too much in the time allotted. I'd say a week in Bangkok (a few days at the beginning and the end) three days/nights for Angkor, and four days for the Golden Triangle rather than Chaing Mai. There is a gorgeous resort, the Anantara at the Golden Triangle that I'd recommend. If you must have a beach, substitute the beach for Northern Thailand. Three places is as much as you want to cover in two weeks.

ok...i have to stick up for the beaches...samui would round out your trip...i would skip chiang mai

so my honeymoon would be:

bkk
angkor
samui
bkk in the order given