A few years ago we went to Luxor for a week.
We decided we couldn't go to Egypt without seeing the Pyramids, so opted to go on a full day trip with the holiday company to see them. Return flights, lunch, trip to Pyramids, Museum and a mosque were included, it was slightly more than I would normally have paid but it was well worth it.
We also went for a couple of days to Hurghada through the company, it was a very long bus journney across the desert (in convoy with other busses, kinda scarey!), but it was a five star hotel and well worth it, and finished off the holiday really well.
But if you've only got a week and want to see some sights, I'd opt for Luxor, and just make sure you go for a decent hotel with somewhere to relax if you want to.
A must is Karnak Temple, the Hypostyle Hall is just awe inspiring.
One of my best holidays, even though we did get very bad 'gypy' tummy half way through!
Enjoy!