Some ideas for your time in Bangkok
*A trip along the river - don't worry about the expensive ones near the big hotels.... just get the BTS to Saphan Taksin station. When you get off the train, go downstairs and you'll see the stand where you buy tickets for the boats. I forget the price (but just a song really) and you get a ticket + a bottle of water and you can get on and off the boat whenever you want e.g. Grand Palace, Chinatown. Lots of interesting sights along the river too.
* A trip to Chatuchuk Market - open on weekends...probably a contender for the biggest market in the world. If you can't buy it here, it probably doesn't exist! Get there early before it gets too crowded.
* A shopping trip to MBK. While there, have lunch at the great food court on the 5th. floor. Maybe have a massage, facial or manicure/pedicure - the place has loads of beauty shops.
* Siam Square -more retail therapy.
* An evening visit to Patpong (Silom) night market - lots of copy handbags, luggage, crafts, clothes etc. as well as bars and restaurants and 'nightclubs' where the girls (and boys) engage in 'interesting' activiities.
* A visit to Freeman night club in a small Soi near Burger King (Silom Rd)- drag show - very talented people sing, impersonate people like Shirley Bassey/Barbra Streisand etc.
* Seeing you're allowing a week in Bangkok, perhaps take a side trip up to Kanchanaburi (lots to do up there...the Bridge, war cemetery, Hellfire Pass and other war history sites,. bamboo rafting, waterfalls, elephant rides, go along the river in a longtail boat) As I've said on here before, I think a day trip is too rushed - book an overnight trip with all transport and accomm included. Lots of trips up there each day so it's easy to get on one.... book at your hotel tour desk. Worth the trip up there.

That should fill up most of the week