I can certainly do this for you but I think you would find it more useful if I told you how to do it yourself.
-First, browse to the Youtube video you want.
-Now, open a new tab or new browser window and go to http://keepvid.com
-Now, back at the YT video, look to the right of it. See a box nect to "URL"? right-click once inside of it and select "Copy" (All the text in it (The link) should highlight automatically).
-Go back to Keepvid and paste that into the space provided at the top of the page. Then click "Download" at the right.
-Right-click on the download link that appears and select "Save As" or "Save Target As". Next, rename it whatever you want, making sure you put ".flv" (No quotes) at the end of the file name (Nothing beyond it). Then save. Once it is saved, you will need an FLV player to view it. Keepvid has a link to one.