I particularly enjoy well-written genfic, but have found precious few examples of this genre starring, featuring, or otherwise centred around Professor McGonagall. Here are some nice ones. If you like them, please leave their respective authors a review!

 

Pro Patria
by Glishara As World War II rages around them, a young McGonagall offers to assist Dumbledore's campaign against Grindelwald.

 

Headmistress McGonagall
by remembercedric Follows McGonagall's point of view during Dumbledore's enforced absence in Chamber of Secrets.

Where She Stands
by amberdiceless With Dumbledore gone, McGonagall has to placate Snape after Harry looks in his pensieve.

A Lioness
by Dragonlady Aftermath of the fifth year -- McGonagall copes with the conditions she finds after returning from St. Mungo's.

A Little Night Air
by penknife Pre-HBP. Snape and McGonagall stand in the Astronomy tower discussing Houses, history, and the war.

Bright Girls Blush
by minerva_fan McGonagall gives Hermione some advice about her future career.