It's almost unbelievable that there are enough guests to fill the seeming billions of hotel rooms in Bangkok!
One of the great things about the city is that there are so many upscale hotels competing with each other that rates are quite reasonable by the standards of other places, especially at the independent places.
If I am staying for more than a day or two I usually stay at the Siri Sathorn these days. It is a serviced apartment/hotel run by the same company as the Sukhothai. Big, spacious suites with fully equipped kitchen, free wifi, free breakfast, spa discounts. And they have a laundrette so if you are traveling for a long time that's a nice thing to have access to. Location is on Sala Daeng Soi 1. So, pretty decent for Silom. About 10 minutes walk to BTS and MRT but they also have a free shuttle van. Advanced booking rates for 1 bedroom units around Bt3000. I really like the place a lot. Friendly service as is the norm. But they always remember me when I return which is nice. I like having an apartment.
For me the number one consideration is location. But I have decided that I will branch out a little bit from my usual pattern when I return later this year. I will have a couple of 1-night stays between trips out to other places so I am planning to spend some time out on Sukhumvit instead of my usual Silom/Surawong. Looking forward to maybe staying at the aLoft if they have decent rates in the Nov/Dec time frame...provided it opens this summer as currently scheduled. But I am also looking at the Fraser Suites on Sukhumvit 11 and a few other places in that vicinity.