A lot of people hate Delphine, but are blind to the truth.
This thread is dedicated to the appreciative thoughts on Delphine.
It is also dedicated to the disagreement of Delphine's appreciation.
Delphine.
Where the other Blades were hunted down and killed off to near extinction, Delphine survived. Her skills to hide and defend herself are worthy enough to deem her one of the most skilled Blades in the history of their existence.
She's also extremely dedicated to her cause. She was one of the first to discover the Dragonborn's identity (it can be argued she knew before anyone else considering she says "So you're that visitor been poking around", implying she figured something was special about the Dragonborn). She helped Farengar find the Dragonstone's location. After finding the Dragonborn she immediately set out to find out what was causing the dragons to come back, managed to help the Dragonborn infiltrate the Thalmor Embassy and pushed the Dragonborn to find Esbern (who ultimately became one of the only two people to know how to defeat Alduin).
As I said earlier, she must be skilled given her ability to hide from the Thalmor for so long. Not to mention she is willing to charge headlong into battle against dragons. Let's not forget her skills when she retrieved the Horn of Jurgen Windcaller - a feat intended for the Dragonborn himself!
She is strong-willed, determined, and she 'gets stuff done'. She personally put the Dragonborn on the path to defeat Alduin. She helped re-found the Blades. Without her where would Skyrim be?
It can be argued that Delphine set events in motion that ultimately saved the world. And don't forget the Blades; their re-establishment clearly will clearly have repercussions in the future, and might even save the Empire from the Thalmor in the next Great War!
Without Delphine the Dragonborn would be sitting atop High Hrothgar meditating until the world ended; so respect the strong-willed, talented master of the Blades.