One of the biggest bottlenecks to watching videos in YouTube is your Internet connection. The page has to load in your Web browser, then the video has to queue up, and other browser tabs can steal priority and bandwidth away ... it's not ideal. DeskTube Lite is a free, separate app solution that requires Adobe AIR, an application environment that DeskTube Lite will install onto your Windows system for you if you don't already have it.
DeskTube Lite is very easy to use and fast for playing, searching, sharing (via e-mail) and making playlists for videos. It doesn't download the video, but rather streams it from YouTube, so the video may still buffer from time to time.
If you're looking for an interface to upload and manage your own videos, which is what a lot of people use YouTube for, DeskTube Lite can't do that, yet. Developer e-works promises an upcoming paid version that will include this and other features. DeskTube Lite also comes in versions for Mac, Linux, Android, and iPhone.
You may also run into videos that won't play in DeskTube Lite. Sometimes a YouTube publisher will disable viewing through the interface that DeskTube Lite uses; in this case DeskTube Lite will provide a link to the YouTube website. One other limitation I noticed is that high-def videos play at the maximum resolution possible with no way to bump it down on slow Wi-Fi connections, as you can on YouTube's site.
On the upside, DeskTube Lite's search works much more quickly than the Web site version and found the video I was looking for right away.
If you're strictly after a YouTube player, DeskTube Lite runs better than vanilla YouTube, and it won't cost you anything, so if you watch a ton of YouTube videos, you're going to want this. If you upload a lot, you'll need to use YouTube's own Web site for the time being.