BACKBEND. Yeah, yeah, yeah, this is supposed to be one of the "easiest" backbends....Riiiiiight. In my opinion, there is no other pose that induces more of a "I HATE THIS" feeling.
However, like everything else in yoga and life, if you do this pose on the regular, that feeling goes away. If you do the pose with correct alignment and an attention to strength, there is none of that--it just feels good.
For me the trick is using strength. If you really tap into the strength in your quadriceps and core, it becomes much easier to go back. Here's a good video from Kathryn Budig