Welcome to Bangkok! Thailand's wild capital is a genuine feast for the senses, full of intense smells, noises and music, unexpected tastes and sights that you'll probably remember for a long time. It also guarantees memorable experiences and adventures at all times. It's so full of contrasts, golden temples popping out between slums, full of tourists scams for example trying to talk you into buying a suit, full of delicious street food and cheap thai massage venues. It's a wonderful chaos.
However I wouldn't really reccomend it for the faint-hearted or for people who hate mess, bad smell or poverty. In such case only a package-tour is an option, but in my humble opinion Bangkok's most valuable experiences are not found in the Grand Palace but among its narrow streets where you sit down on a plastic chair and dine with the locals.
Okay, but to deprive Bangkok's main cultural attractions is a sin as well. They indeed are grand, and you just cannot miss them. The Grand Palace and an endless number of temples would be enough to occupy you for a few days in Bangkok.