So, I've updated the youtube tags this evening. You'll now enjoy the full youtube player that you get on the website right within any thread or post. There's no need to change your BB code, it's all done automatically.
One thing I'll quickly mention is that there are also a couple of tags which aren't always widely utilised - which I'm thinking is down to nobody actually being aware they exist. These are the wyoutube and hdyoutube tags. These are pretty self explanatory, one allows you to post the video in widescreen and one allows you to post it in a bigger window (also in widescreen ratio). The HD YT tag is actually at 800x480 resolution, the reason for this being 1280x720 resolution is still a bit too high for an embedded video - however it is noticeably bigger then your standard Youtube tag and allows you to get a better experience out of HD youtube movies without having to go full screen.
Here's the tags all in action:
Standard Youtube Tag
High Definition Youtube Tag
As you can see, the HD youtube tag doesn't default to 720p+, the reason being is that it's not feasible to force choose this in the embed code. However, the option is still there and still allows for a more pleasant viewing experience.