(Former Review, July 03, 2011: By far the best-known social networking site in the world. It may have its problems, but remember, this site is dealing with an average 510,000,000+ daily users on a regular basis.)
I haven't used Facebook in nearly three years after having my primary Facebook account removed due to alleged abuse. I seriously doubt the validity of this reason, though, since just before being removed I was raving about how excited I was for Google+ and how my friends should try it out. Apparently, Facebook doesn't appreciate competition.
Having said that, Facebook is the most popular social networking website in the world, though it was recently surpassed by Google+ in terms of registered users. However, Facebook has displayed on multipled occasions a complete lack of respect for user privacy and security, being cited for selling personal information to third parties and requiring invasive security checks in order to retain an account. Moreover, the userbase as a whole has degraded to the point of teenage melodrama, ignorant opinions on the behalf of belligerent adults, and an all-around absence of any sort of intelligence or logical reasoning in the comments section.
In addition to the above violations, Facebook has stolen a number of ideas, concepts, and features from Google+. Evidence of this can be clear when comparing Facebook's layout and features before the beta release of Google+ and the same afterward. A system very similar to Google+ Circles and news feed filtering was introduced, along with a user interface which was almost identical in layout to Google+. Video calls and chat updates also matched Google+ features, lending further credence to the theory.
Lastly, Facebook has expanded from being simply a social networking site to a corporation seeking to monopolize the field, purchasing rights to ownership for the Oculus Rift, which it plans to use in its video chatting. Unlike Google, which although expansive, tends to seek to innovate and revolutionize the technology and companies it purchases or develops, Facebook is essentially copyrighting everything it can to restrict other social networking platforms from thriving.
Overall, I am very dissatisfied with Facebook and do NOT recommend it. I'd recommend Google+ instead, though even MySpace is arguably preferred over Facebook. I still own a Facebook account, which I was forced to open with a new email and an entirely fresh start, but this is solely to park my alias and identity into the database in order to prevent any chance of impersonation, were that to ever be a concern.
In terms of safety and security to your computer, Facebook is safe as a website, though the content is riddled with bots, spammers, scammers, and identity thieves seeking to install malware and spyware onto your computer or device. Also, fake accounts are quite rampant on Facebook, especially since the site has tried to enforce proper identification.
In summary, if you want a cancerous cesspool of stupidity and ignorance as a userbase, coupled with an invasive and inconsiderate company cited for privacy violations, Facebook is the social networking platform for you. If this doesn't appeal to you, probably any other social networking site will better suit you.
As a final note, you may have noticed I am quite a fan of Google+. That's true and I wholeheartedly admit it. I joined the site during it's closed beta and haven't looked back. Unlike Facebook, I am thoroughly satisfied with the services Google+ provides and would recommend it to anyone. This is just my personal preference, though, and if you've had bad experiences with the site or with Google, I totally understand. So have I. Unlike Facebook, though, Google resolved my issues and did so without being douchey about it. For that reason, and many others, I'll gladly deal with Google over Facebook any day.