I don't know of any master-list (depends a lot on group, gear etc etc), but here's a personal list written off the top of my head - in a general order and with some comments about cc-needed when undergeared.
### Easiest group
slave pens^ - as soon as you have the hp to survive the double pulls, this is easy and fast badges. A couple of large pulls where cc is useful until you out gear it.
mechanar^ - used to be the favourite badges grinding spot, now gives fewer badges but still sun eater and the epic dps legs. Warlock and one cc helpful here.
Ramparts^ - I farmed this place for my HH rep, no hard hitters in the trash and only the dragon gets a bit exciting at times.
underbog - I don't enjoy this place (personal dislike), but apart from one double hard hitting pull it's pretty easy going.
blood furnace - second boss can be a real pain, and a lock helps on the pulls right at the end - those demons hit HARD.
steamvaults - a couple of cc'ers (mage, hunters) make the trash easy, only two single bog lord pulls who hit hard. Warlock makes the first boss easier, end boss is a dps test.
Botanica - first boss is the hardest (imo) after that it's very similar to normal.
Arcatraz - Nice heroic if you're short on cc, very few multi-pulls. First boss can be a pain, but can be skipped if needed.
Mana-tombs - I generally wear green shadow res gear for the first boss (personal preference), cc'ers and interupts helpful for the healers and casters.
Shattered Halls** - Was much easier than I was anticipating, but probably cos I'd gotten myself stressed about multimob tanking. Tank and healer need good gear.
Shadow Labs** - Was also easier than I imagined, if you can stop your dps killing each other while mc'ed for the first boss A cc or two can help as some of the groups are pretty big
Black Morass** - Once you outgear this place, it's the easiest and fastest way to collect badges - I was pleasantly surprised.
^ - These were the heroics I ran soon after reaching 70 and before Kara (before 2.3 badges gear) etc.
** - Only recently run these (full kara gear, some early 25 man gear and 2.3 badges gear)
Omitted Sethekk, Crypts and Durnholde as I have very limited experience in them.