One thing I think is missing from the discussion is what Bungie is doing to console gaming. There are a couple features in Halo 3 that used to be reserved for PC gamers. The ability to edit maps, take screeen captures, and save and review gameplay films is pretty huge in my opinion. Plus their integration with their website for these features is great. Early next year, they will launch their own version of "YouTube" where in game video is automatically uploaded to the user's channel and converted to usable video format.
Now that Bungie has done these features, and done them well, I know it raises the bar in terms of what I want out of a console shooter. I would hope that the ability to edit and share maps, screenshots, and flms becomes a trend in more games. It's great to be able to save and relive fun moments with friends without always running your games through the capture card.
It's hard to see how they wouldn't set trends seeing how Halo 3 still regularly rules the XBL unique user list, even with tons of other big name games on the market, and continue to rule the top of the original Xbox user charts with Halo 2.
Ledger comes across as pure scary at times. Since you haven't seen it, I won't say much more, but I will say Ledger did an amazing job. Right down to his speech, facial mannerisms, and erratic changes in demeanor, he sells crazy. So much so that, for me, Batman was actually a secondary character.
The joker came off so dark, violent, and twisted that it made me several times wonder how the movie 1: stayed PG-13 and 2: Was still a Batman movie.
I'd have to say Ledger is the better Joker.
At the source of every error which is blamed on the computer you will find at least two human errors, including the error of blaming it on the computer.