[QUOTE=Argent Towers]
Well, there’s someone here who will definitely be able to help you. What’s his name again? Bangkok Bob? Thailand Tom? Whatever it is, he knows his way around that corner of the world. I mean, many of his recommendations will probably involve someone sucking your dick, so I hope you remembered to pack that. (I kid.) Anyway, he’d be the guy to ask.
[/QUOTE]
Nah, this is Bangkok Bob. But I’ll try to keep the dick-sucking recommendations to a minimum, although … if the OP or anyone else coming here (pun intended) is interested, I could give the names and locations of some of our BJ bars, including one that’s a nationwide chain, with establishments in three cities. 
But for more conventional tourist advice, I’d say if the OP has only a week to go somewhere, Siem Reap would be perfect. You really need a minimum of four days to do Angkor Wat properly. There are some tour agencies that offer to take you around them in half a day! Screw that! You could easily spend a week exploring Angkor Wat, especially if you visit the more outlying ruins. If you’re also interested in Phnom Penh, I’d say do four days in Siem Reap and the rest of the time in Phnom Penh. A couple or three days for Phnom Penh are plenty.
For Kayeby, for Chiang Mai city, I can recommend our usual place, the Montri Hotel. That’s where we always stay, and we were just there in May. The location is absolutely perfect, just inside the Pratu Thapae (the eastern gate to the Old City). Decent rooms (renovated recently) with air-con for 850 baht; at the current exchange rate of 34 baht to the US$, that’s only $25. The staff are friendly, professional and very helpful. They charge a bit more if you want breakfast included, but I would suggest you not do that; the restaurant downstairs is only so-so, and there are some very good breakfast options all over that area. The location was always the best, but it’s even better now that Ratchadamnoen Road, which the hotel is at one end of, has been turned into one long street market every Sunday. It gets crowded out there on that day, and it’s nice to be able to just pop up to your room for a break. The Montri does not have a website, but their e-mail is montri_hotal@hotmail.com, and their phone numbers are (053) 211-069, and (053) 211-070 and (053) 418-480. Note that if you’re dialing from outside of Thailand, the (053) part should be (6653) instead. Be sure to specify you want a room toward the back, to avoid the noisy traffic outside the front down by the Pratu Thapae. For us, we honestly would not consider staying anywhere else. (No, we do ot own the Montri Hotel or have any business interest in it.)
I still recommend you go a little farther afield, too, and make the trip to Mae Hong Son. What a lot of people do is take the 35-minute flight one way and then the 8-9-hour bus ride the other. Great views on the bus ride, especially if you take the northern loop, which I recommend over the southern loop. Another advantage of the northern loop is that the towns of Pai and Soppong are good places to stay for a couple of days in their own right. Pai used to be just a sleepy little mountain town, but it’s developed quite a bohemian Thai music scene in the past decade. We just stayed at the Pai River Corner and can recommend it very much. Owned and operated by an Australian-Thai couple. Beautiful location, peaceful. We were there during low season and so got a special deal, 1500 baht a night for a regular room; I believe that’s often up to 3600 baht during the high season! But if it’s a good place to treat yourself. Unfortunately, the regular rooms don’t have any English-language cable, only the higher-priced ones have that, and I always like to keep up with BBC or CNN. But the place is nice enough that I didn’t care about that. They were building a pool while we were there. We had the Thai tennis champion Paradorn Sichapan for our neighbor one night. Pai also has some elephant camps nearby, and we can recommend Thom’s Pai Elephant Camp. You can see the wife and me with one of their elephants here. The bareback rides through the countryside and river are pretty cool. It’s actually possible now to fly from Chiang Mai, but I don’t think it’s worth it. The flight is only 20 minutes, but unlike Mae Hong Son town, Pai is only 3-1/2 hours by bus or van from Chiang Mai, and it’s a nice drive.
In Soppong, there are a couple of good options in town now, although we’ve not stayed there. Back in my days in the province, I spent a lot of time in Soppong but always stayed with a friend who used to live there. There was no electricity at all back then in the entire area around Soppong; now they have electricity and a nice-looking place that even has a pool. Still, I recommend heading for Cave Lodge 8 kilometers outside of town. There’s electricity out there now, too, and the road is even paved now. The owner of Cave Lodge is an Aussie named John Spies who has lived there practically forever and published several books about different aspects of the area. Nice guy, and he can be very helpful with information. He’s quite an expert on the extensive local cave system, and he speaks fluent Shan (the Shan are the majority in the province; Thais are in the minority). Bungalows at Cave Lodge tend to be rather basic but okay and cost anywhere from 200-450 baht.
In Mae Hong Son town, there are a couple of fancy places on the edge of town, but I’d go with the Baiyoke Chalet inside the city. I’d rather be inside town. I was living in the town when the Baiyoke Chalet opened in 1988, and it was super-nice back then, what with the all-teakwood decore. Looking a bit worn now, but it’s still good, and the location is great. I think it’s 1000-1400 baht a night now with breakfast. Ask for a room away from the front and on an upper level, to avoid the noise of the street and the restaurant/lounge. Telephone (053) 611-536. I think there may be some new places in town, too, since we were there last (did not make it to Mae Hong Son town itself on our trip in May), so you might want to surf around to see. But I recommend picking a place in town rather than on the edge or out in the countryside. Pretty little city (Mel Gibson’s Air America filmed there. The movie’s crap, but it will give you a good idea of what the city and countryside look like.)
For the South, I’m afraid I cannot be too much help. We’ve not spent a lot of time down there. When we go to the beach, we don’t care about “activities,” we just want to laze on the beach, so Hua Hin or the immediate area is where we always go. Just a few hours from Bangkok, and the beaches are nice, but there’s not much in the way of, say, snorkeling and diving and such, and it’s not drop-dead gorgeous like other places much farther south. I thik Ale can probably help you with recent information on the South and diving, but Krabi should be good, and Lonely Planet has named Railay Beach in Krabi province as Thailand’s best beach (but we’ve never been there). I’d say Phang-Nga province is good, too. Phuket is very popular, but in my opinion it’s very overrated. On the other side of the peninsula, Samui Island (Koh Samui) is popular, but I seem to hear nothing but complaints about it from people. On the other side of the Gulf of Thailand, off our Eastern Seaboard toward Cambodi, Koh Chang is better than Koh Samet, but Samet is easier to get to; for either island, the farther south you go along its coast, the better it is. Avoid Pattaya at all costs.
The Northeast is an interesting option, too. Fewer than 2% of tourist arrivals head for the Northeast, our poorest region. The drawback is that finding people who speak English could be a problem outside of the larger areas, but it’s a very interesting region. I would recommend the city of Nong Khai, at the end of the train line and sitting on the Mekong River across from Laos. There’s a bridge there for easy access to Vientiane. We’ve not been there for years, though, so cannot give you any specific recommendations.
If you are interested in Laos, I would not recommend traveling overland between Vientiane and Luang Prabang. It does not happen very often, but occasionally bandits or rebels or whatnot will ambush buses out of Vientiane, killing all aboard. And I would never fly domestically in Laos; Lao Airlines has a poor safety record domestically, to say the least. They maintain their international-route planes much better, and we have flown that airline between Chiang Mai and Luang Prabang. I hear traveling to Luang Prabang by river from Thailand is a fun option, too.
For Bangkok, we always recommend the Royal Hotel in the Rattanakosin area, the original Bangkok, “old town” I guess you could call it, but it’s never referred to that way. Great location, and unlike many Bangkok hotels, they do not have double pricing. Thais and foreigners get charged the same, about $35 a night or so if I remember correctly, maybe a little less. Many hotels, especially in Bangkok, charge foreigners a special higher rate. Has a pool, too. The touts outside the door can be a little aggressive but not too bad. It’s not near the Skytrain or subway, as they will not permit the disruption in this historic area that would be needed to extend the lines to there, but unless your main purpose in coming to Bangkok is going on a shopping spree, the Skytrain is not necessarily all that necessary for you. I don’t have any contact info for the Royal at hand, though; Googling it seems to come up with just hotel-reservation websites.
You can find up-to-date info from other travelers at Lonely Planet’s Thorn Tree Travel Forum. For Siem Reap, indeed all of Cambodia, Gordon Sharpless’ Tales of Asia website is invaluable, and he himself runs the Two Dragons Guesthouse in Siem Reap with his Thai wife.
Also, you mentioned you’d be here in November. November 12 is the date this year for our Loy Krathong frestival. That’s not an official holiday, but it is hugely popular, and the North is the best place to experience it. That means booking ahead is important.
Hope this is of use. Have a good trip!