Although though the terrace at Skyfall is small, considering it is free between 5 and 9 pm, it provides some pretty spectacular views of Las Vegas.
Some spectacular views
The best views of Las Vegas and free entry? The only reason not to go might be its location at the far southern end of the Strip.
If you are walking to the venue, the best idea would be to go to the Excalibur and then catch the free monorail which connects the hotels.
Skyfall is fantastic for both dining as well as an evening drink. The only negative is that if you are looking for somewhere to dance the night away, the tiny dancefloor can feel a bit limited.