Okay I remember reading a fic years ago where Harry went back in time and taught his parents at Hogwarts(yes I know how stupid that sounds) but, what I'm wondering is if there are any decent fics where Harry's a teacher?

 

Lolwut? What a fantastic story.

 

There's a fic where he travels back to founders era and teachers a year. I remember the story was decent enough (not library worthy though), but I forget the name. Shouldn't be too hard to find as it is a rare pairing and 100k words.

There is also this http://forums.darklordpotter.net/showthread.php?t=9074 which may or may not be the story you mentioned.

 

Egad Sesc, warn a man.

 

On a related note, are there any decent post-Hogwarts fics where Harry is a teacher and the story is not from the perspective of one of the children?

 

Well, I know of one, but (as Aekiel's post alludes to with many stories in this genre) it's more about Harry's romance with a student than the actual teaching and such, and from the student's perspective.

http://www.fanfiction.net/s/6421660/1/bTonight_b

 

it's an oldie but I found it to be worthwile: Like Some Song You Can't Unlearn

http://www.ficwad.com/story/47735

 

Deadwoodpecker did one as an AU where Ginny was a couple years younger than canon. Harry comes back after the war to teach Defense Against the Dark Arts and she's in his class. They strike up a relationship. It's much more angsty than her other work, though decently written if you can accept a Harry/Ginny story that doesn't Weasley-bash.

Spoiler

Ginny was kidnapped by Malfoy and repeatedly raped by the Death Eaters before being rescued. There's more to it than that, but I won't spoil it. Harry's pretty much withdrawn from the world.

Nonjon's Where in the World is Harry Potter and sequels would also qualify.