Friday afternoon, Blizzard employee Bornakk posted a poll on the General boards to find our favorite 5-man dungeon of the Burning Crusade. As you can see in the above image, the Caverns of Time is rocking the charts.
I can't say I disagree with the numbers there, they're pretty close to my opinions as well. Old Hillsbrad and the Black Morass offer something that most of the other instances don't: Fast pacing, minimal trash pulls, and a story element. The instances aren't very long, either. Black Morass is what, thirty minutes? These dungeons on Heroic remain difficult and dangerous, adding some new elements to the instance, such as a necessity for speed and stealth when it comes to the patrols in Old Hillsbrad. Some of the other Heroics do this as well, but most of them coast along on 'ow this mob hurts a lot'.
The current runners up are the Mechanar and the Shattered Halls, though they're pretty far off from matching the Caverns of Time in terms of popularity. I can't help but notice that both of these instances have a small element of setting the pace, similar to the CoT. The Mechanar's final gauntlet has an element of urgency about it, you don't have much time to catch your breath before the next wave. Shattered Halls also has a similar gauntlet between the first and second bosses. You keep moving, or you're in trouble. As an added bonus, taking a Protection Paladin and a few Warlocks to Shattered Halls is the most fun you'll have. Period. Yes, I may be a little biased.
It's fairly easy for me to see why the Caverns of Time is dominating that poll, they're so different from the pull-drink-pull mob parade of the other dungeons. I hope the devs take these poll results to heart and step up the sense of urgency and danger in Wrath of the Lich King instances. The level of excitement in Black Morass just isn't topped by anything in the Burning Crusade before the raiding scene. Heck, not much in the raid scene matches the rush of your first BM run, either.
If you haven't voted in this poll yet, go do it! The poll closes on February 1st so you have quite some time left, but if you're like me and wait until then, you'll probably just forget. So, don't wait, eh?