The major highlight was the Royal Grand Palace, it is indescribable, a sensory overload. Wat Po, next door to the Grand Palace is quite grand also.
Personally I enjoyed Bangkok itself. It may have bad air pollution but it makes up for that by being vibrant and colorful.
Quick Tips:
Simply take Bangkok as it is; don't try to compare it to anywhere else and allow yourself to enjoy. For the Tech minded a visit to Pantip Plaza is a must.
Best Way To Get Around:
I used taxis and feet. Feet were more direct if going short distances.
The Skytrain is fast, clean, efficient, and cheap. A tourist pass for one day is Bht100 around A.00.
I didn't use tuk tuks in BKK but I did in Hua Hin as I was staying 4ks out of town.