Just get a download extension for your browser. On FireFox I use Flashgot and DownloadThemAll.

I bought an Amerisoft video package some time ago and it have this feature. It's great. There's also an old Ashampoo product that was great at this.

I'd like to download YouTube videos to an iPad. Any ideas on that one?

Find out what type of files your ipad uses then see if any of the converters mentioned will convert to that. Don't have an iPad so I don't know off hand.  

http://www9.any-video-converter.com/
Seems to be some info here for you. There are paid and free versions. I use the free version for my Nook HD+ and it does everything I want it to.

If you use Firefox, there are free add-ons/extensions that will do the job.
 
I use YouTube Best Video Downloader 2.  Once you've installed it, you'll see a Download button below each YouTube video offering a choice of video quality. 
 
Though I also have a video capture utility, it sometimes fails depending on the video source.  The download from the add-on, on the other hand, has so far worked flawlessly.  Plus, it's a lot easier, as I don't have to launch a separate application.

The website  should help you : ) very good one.

Clipgrab is my favorite free downloaded application... has options to download at any quality level and even convert to a multitude of other formats.