I really enjoyed my visit to the neon museum in Las Vegas. Having been to the city 4 times, this is one of the only tourist attractions I had not seen. I debated whether it would be worth the price ($19 for day time, $25 for after dark) for my husband and I to see it, and I felt it was. A little more than I wanted to pay, but I'm glad I did it.
The tour guide was great. He was very passionate about the history of all the signs, which he went into detail for almost every sign in the park.
I didn't realize until reading reviews that not all of the signs would be lit up during the night tour. I had already purchased my tickets (which you must do several days in advance, online, by the way) for the night tour. I'm not sure it was really better than seeing it the day time, however, cool to see colored light projected onto the signs but most were not actually lit themselves. If you can't get tickets for the night tour (they sell out quicker), just do the day time one! Only 6 or 7 signs actually work.
Parking was not a problem. They have their own private lot and there was plenty of space when I arrived 20 minutes prior to my tour (and it was a Friday night too).