I think Cram and either Howie or Lockhart are great commentators, they raise their voices only when necessary - which was not often. The guys who do all the snowboard cross/snowboarding stuff are very excitable, but that fits in with the vibe of the sport so makes perfect sense.
My real beef is with commentators who can't speak English properly. John Jackson, the 'colour commentator' for the sliding sports could barely get through a sentence without the English language taking a pummelling. I'm not a pedant, but a constant stream of 'lines what they're driving' 'good starts what they're making' type comment is fairly unbearable.