This is such an interesting topic, I always look forward to doing these every week. I find myself wishing so often for certain characters to get their own book or series and now I finally have the opportunity to let everyone know which ones!
1) Neville Longbottom.
When you think about it, Neville has actually had a really interesting life. In fact, in a way, it's similar to Harry's in terms of tragedy, isolation and the continuous fear of death. I feel like Neville's potential part in the prophecy was a little overlooked and I think he would have a pretty fascinating childhood story, as well as his life as a Hogwart's student.
2) Professor McGonagall.
To be honest, I would love to view life from any Hogwarts Professor's POV, but I think McGonagall is awesome! Can you imagine the Hogwarts Staff Room conversations? Her thoughts as she has to give Harry detention (again)? and I bet that she transformed into a cat to listen in on private conversations all the time.
3) Scabbers/Peter Pettigrew.
Okay just think about this one. The entire first three books from Peter Pettigrew's viewpoint. He would hear everything the trio said and not be able to do a single thing about it! Perhaps, while everyone was sleeping, he just transformed back into a human and went for a walk. I'll bet there are a ton of hilarious 'being chased by Crookshanks' stories too!
4) Lily Potter.
This is a pretty obvious one really. I would just love to get her view on Hogwarts life, meet some new professors and watch her fall in love with James. I'll bet her childhood friendship with Snape would be the most heart-breaking, emotional thing to read too!
5) Bellatrix Lestrange.
I never really felt like Bellatrix Lestrange, as a character, was given any real back-story or motivation. She was literally just a psychopath. Why did she join Voldemort? Were they ever romantically involved? Does she have a tragic story that turned her into the craziest woman alive, or was she always like that?
6) Draco Malfoy.
Okay so this story would probably involve an awful lot of whining and moaning about Potter, but there would probably be some pretty cool bits where he tries to understand jut what his Father is up to and his own feelings on that. Not to mention, I am desperate to know exactly what Draco did in his school Summer holidays...
7) Luna Lovegood.
This would literally be the Harry Potter story with added Nargles. No, seriously, I want to read some cute Lovegood moments and maybe find out a bit about Luna's Mother. The Lovegood back-story has always intrigued me! Also, how did she cope with being captured and taken to Malfoy Manor?
8) Rubeus Hagrid.
I would love to read a bit of Hagrid at school, wouldn't you? I bet he was the most enthusiastic pupil of the lot and was absolutely heartbroken when he lost his wand. It would just be interesting to find out about some of his early Gamekeeper years, and interactions with other Hogwarts Students, pre-Harry.
9) Arthur Weasley.
Does anyone else want a 'Mr Weasley's Guide to Muggle Inventions', and then just page after page of various Muggle things and how they work (except they don't work like that at all)? Well I do. I would love to find out more about the inner workings of the Ministry Of Magic and he would seem to be the man to ask.
10) Gilderoy Lockhart.
Who on earth doesn't want to actually read Gilderoy Lockhart's books? They sound like such fun reads! It would be really cool to try and figure out at which point Gilderoy pulled out his wand on the real Wizard who braved all these foul beasts, and wiped their memory.