There are numerous YouTube video downloaders out there, but BenderConverter is the best one I've used – at least until something better comes along.
Unlike other downloaders that require you to install something at worst, and wait a few hours at best, BenderConverter (named after that awesome Futurama character) does all the dirty work. You simply paste the YouTube video's URL, select the format you want to convert the video to, click the Convert button, and wait for a few minutes.
After those few minutes are up, a Download button appears. Click on it, and voila! Your converted video downloads straight to your computer. Coupled with a good download manager like FlashGet, BenderConverter literally becomes the fastest way to play online videos. Given our sucky Internet connectivity, it's sometimes better to process a vid through BenderConverter than load it on YouTube. At least you don't have to wait for the video to load to watch it again.
Because BenderConverter supports many formats (MP3, WAV, AVI, MPG, and MP4, just to name a few), it's easy to turn that awesome soundtrack into a music for your playlist, or build a schaudenfreude video playlist for that lazy afternoon. The only missing feature is batch processing – where you can direct the service to convert multiple videos and provide it as one downloadable ZIP – but otherwise, I have no complaints.
BenderConverter also works on Daily Motion, Vimeo, TwitVid, Veoh, Google Video, and loads of others. Here's another reason to make foolish ones regret uploading that compromising video! Fulfilling the adage "once it's online, it spreads relentlessly" has never been this easy! Here are some classic online videos to get you started:
Of course, I'm always open to suggestions. So if you know a better video download service, feel free to share below.
Another option: 3ouTube. – Editor