Valley of Fire State Park is about an hour north of Las Vegas, and definitely worth the trip, especially since I've never really been to the southwest (Planet Las Vegas doesn't count). It really was so beautiful. The desert is a very interesting environment, and the red sandstone rocks look so dramatic against the blue sky.
To be honest, I don't like this city very much, but my boyfriend was traveling for all of January and it was easier for me to visit him than for him to come home for a weekend. This time, we avoided the Strip as much as possible, only venturing out briefly so I could buy a bathing suit, and then hurrying back to our hotel to enjoy the hot tub on a beautiful afternoon. We had some very good meals, one at StripSteak, the best steak I've ever had and duck fat french fries. Valley of Fire was definitely the highlight of my weekend though. Now that I've seen the desert, I won't mind if I have to go back again next year.
UPDATE: I've added the rest of my Valley of Fire photos to this Flickr set, including some in black and White