MiG, what YouTube BBCode mod/version are you using?
I’m using this one at version 1.7 (although now that I look, I see that 2.0 was recently released), and I can just input
http://www.youtube.com/watch?v=LHY8NKj3RKs
and a variety of other syntaxes, and it’ll automagically figure it out, and use the default YouTube player size if you don’t specify one.
I’m just saying, I find the current implementation on HTMF a little bit clunky.