Moody, it says in GOF that it took both Crouch Jr. and Wormtail working together to take down a surprised Moody. Plus, Moddy has far more to his credit (Bellatrix, Antonin, the Lestrange brothers and several other deatheaters that Moody killed in the first war).

But really, if Crouch can only barely subdue a surprised Moody with help, without help he is screwed

 

hmm did not think of that but here is another one

Bella vs Lucius

 

Bella Lucius is a pampered little pofta. He couldn't take down a bunch of 5th years and I think Bella would really like to rip his throat out.

Aragog Vs Hagrid

 

Aragog would win, he has 8 legs plus hes huge, Hagrid while stron only has 2 arms and is not the sharpest knife in the drawer also the fact that hes not a very accomplished in magic is a downside for him. Besides, Aragog has his family thats got to count for something.

Narcissa vs Tonks

 

Tonks.

We have no canon proof that Narcissa can even duel.

A trained Harry vs Bellatrix.

 

depends how he was trained and by who. if trained to fight with dark spells... then maybe Harry, if not, then bella all the way.

Lucius Vs Snape

 

Snape. Lucius is jut bad at everything. Snape, even though I hate him, is presumed to be a reall good dueler

Fleur v Hermione

 

Fleur.

She graduated from school so she knows more spells.

Voldemort vs. Grindelwald?

 

Voldy, he has the horcruxes


Snape Vs Lucius

 

Is that supposed to be different from Lucius versus Snape?

Ill give you different one

Winky Vs Fenrir

 

Winky, she'd tie him up and dominatrix him like a good little doggy.

Giant Squid Vs. Merfolk.

 

Merfolk.
Giant Squid is supposed to be an giant kraken and what he/she/it is doing? He/she/it isn't killing anyone? So IMO he/she/it is an retard and pussy.

Mrs. Norris vs. Crookshanks?

 

Crookshanks. Come on; he's described as being like a small tiger, compared to the scrawny bag of bones that is Mrs Norris.


Fleur vs Tonks?

 

Tonks.
She is an auror - and that means something - I think.

Hermione vs. Luna?

 

Luna. she could use those wierd creatures to help her...

(junior) Crabbe Vs Goyle

 

The Moving Stairs of Hogwarts - they would fall from them .
Seriously - I don't know. We don't get much information about Crabbe's and Goyle's magical power. So it would be save to assume they would knock each other out cold.

Tom Riddle (diary version) vs. Harry Potter (HBP)?

 

psshhhhhh even Dobby would have been able to beat the shit out of Harry in HBP.
So I say the diary.

Pansy Vs Lavender

 

Pansy. Lavender seems too obsessed with her looks.

Dobby vs Kreacher

 

Dobby, he is too hyper active for an old sod like Kreacher

Crabbe Vs Goyle

 

again same i think not enough info on them, but ill go with goyle.

Ron Vs Neville