Background Information
The Space Needle was built as part of the Seattle Center, which was built to host the 1962 Seattle World's Fair. At the time of its construction, the Space Needle was the the tallest structure built west of the Mississippi. Since the end of the World's Fair, the Needle has continued to be a popular tourist attraction. It also includes a rotating lounge near the top of the Needle, giving patrons a 360 degree view of Seattle and nearby Puget Sound. Even if you don't want to hang out at the lounge at the top of the Needle, you can still enjoy all the view from the observation deck as well.
Plan Your Visit
There are several things you should know while planning a road trip visit to the Space Needle. From a logistical standpoint, your biggest problem will probably be parking. Unfortunately all the most convenient parking options around the Seattle Center cost money. Actually getting admission to the Space Needle will be a bit costly as well.
Since the Seattle Center is located just north of Downtown Seattle, parking can be a challenge, although for a fee you can park in one of three main parking lots. There are also a few EV charging stations available for $2/charge. If you don't want to mess with parking near the Seattle Center you can park somewhere else and take public transportation to the Seattle Center campus, such as the famous monorail, or King County Metro.
Once you get to the Space Needle, if you want to actually go to the top, you need to buy tickets for the elevator. They are a bit pricey, as you will need to pay anywhere from $25-$37.50 per person, depending on what age you are and when you go. If you want to visit several of Seattle's main tourist attractions while in Seattle you can get discounts if you buy the City Pass. The City Pass provides admission for the Space Needle, the Seattle Aquarium, The Museum of Pop Culture, The Woodland Park Zoo, and the nearby Chihuly Garden for a fraction of the cost if you were to pay for admission to each separately. Buying a ticket to the Space Needle will give you admission to go up the elevator, and also to check out the sights at the observation deck near the top.
The Loupe Lounge
The SkyCity Restaurant closed in 2017 when renovations began on the Space Needle, and even though the renovations are done, the restaurant remains closed. You can, however, enjoy the Loupe Lounge. One neat feature added to the Space Needle as part of the 2017 renovations is the glass floor. The Lounge still rotates like the old restaurant did, but now features a glass floor so you can not just enjoy the views around you, but you can also see what is going on right below you at any moment. This is a pretty neat feature, although not something I would enjoy if I had a fear of heights. (Although lets face it...if you had a fear of heights, you probably aren't going to the top of the Space Needle in the first place.)
Reservations for the lounge are available for up to two weeks out, with a new batch of reservations being released every Monday. If you are interested in learning more about the Lounge or making reservations, you can find them here.
Conclusion
Having been there, I can tell you, in my opinion, that the Space Needle is worth visiting once or twice, but the price of admission is too expensive to do all the time. If you have the time and extra money to spend, it is worth it, but if you are sightseeing on a budget, there are many better and cheaper options to spend your sightseeing time on than the Space Needle.

