Today I had to go find Esbern for the MQ, but when I make it to his doorway, the little peep hole slides open, and Esbern is just standing there moving his head and gesturing, lol, but he doesn't say anything or unlock the door. I am not using any big mods or mods that effect him or the MQ. I did skip talking to Brinjholf and just went stright to the ragged flagon, bribed one of the TG memebers to tell me where he is, and went from there.

If you using mods of any kind that are not updated for the recent game patch they will cause problems. Remove all mods and try Esbern again.

Are you using the Unofficial Skyrim Patch? The 1.6.89 title update made changes to dialog to address "rare issues with dialog and subtitles" and causes a conflict with the multitude of dialog changes made in the USKP. You can either roll back to 1.5.26 if you have a backup available or if not, either disable the USKP or use one of the edited versions of it discussed in http://www.gamesas.com/topic/1383605-wiprelz-unofficial-skyrim-patch-thread-8/. This may be the cause of this missing dialog, though this has been reported before, so may be related to other mods. It is also possible that trying again from an earlier save may fix the problem.