*Cracks knuckles* Let's see here...
The Drake of the West Wind is easily obtainable now, I'd imagine. You need 200 Commendations that you get through doing the dailies in Tol Barad. The Drake of the North Wind, which is "easy" I suppose, is from Normal/Heroic Vortex Pinnacle, and can be farmed over and over. (I'm currently working on getting that myself *well over 600 runs at this point,* but I know MANY people who get in within their first 50 runs, and many that have gotten it in their first 10. Patience is key!)
Another one that requires the same patience is the Vitreous Stone Drake from Normal/Heroic Stonecore.
Doing the meta achievements for Icecrown Citadel and Ulduar are extremely easy now. Ulduar can be one-shotted easily, and give the Rusted Proto-drake 10-man, and the Ironbound Proto-drake from 25-man. For ICC, you're given the Bloodbathed Frostbrood Vanquisher for 10-man, and the Icebound Frostbrood Vanquisher for 25-man.
Invincible would simply take time and weekly groups, but it's pretty darn easy now.
The Netherwing Drakes are super easy to get. Go to Shadowmoon Valley and begin the quest-line there, and you get an abundance of dailies, as well as an egg (when found) that can be turned in for reputation.
If you have a character that can solo Kael'thas in Tempest Keep for Ashes of Alar; it's super easy, but has a weekly lock-out.
For ground mounts if you have a character that could solo Alysrazor in Firelands, she just requires some patience for the Flametalon of Alysrazor to drop.
Baron Rivendare's Deathcharger from Stratholme is an easy ground mount to solo.
Reins of the Fiery Warhorse is an easy ground-mount (but generally requires extreme patience. =P) from Karazhan. Raven Lord from Heroic Sethekk Halls. White Hawkstrider from Heroic Magister's Terrace.
Err... there are a bunch of mounts at the Argent Tournament Grounds that are obtainable through Champion Seals.
There's a lot more than my brain is pooping out on right now. If you have the ability to sit and listen for NPC scan, then you can look for the Time-Lost Proto-drake in Storm Peaks, and for the Phosphorescent Stone Drake in Deepholm.
Um, I'll give you my battletag, and I'll gladly help you obtain some of the ones that might be a pain in the rear. Whenever I get Flametalon for myself, I'd gladly help you farm her! =)
Here's my Battletag: Phedrea#1817
Edited by Ophinia on 2/4/2013 9:34 AM PST