Books, movies, tv, real life, whatever.
Spawned by a thread discussing Back to the Future and mentioning Doc Brown.
My candidate: Walter Bishop from Fringe. Invented some cool stuff and was institutionalized for a time. Qualifies on both counts.
So lets hear yours or I’ll crush you like insects (kidding).
Zer ist only vun truly mad scientist, und zat mad scientist is Dr Strangelove.
OK, he might not be the maddest or… scienciest… but it’s got to be up there as one of the most critically acclaimed films with a mad scientist in it.
If you allow animation, my vote is for Professor Hubert Farnsworth.
Does Q from the James Bond films qualify as a ‘mad’ scientist? He would have to be at or near the top of my list.
[Pedant]
Almost all mad scientists in fiction are reallyMad Enginners, not scientists.
[/P]
Ok, now with that pet peeve out, carry on. 
Mine is Dr. Finklestein from The Nightmare Before Christmas, he can literally scratch any itch in his brain.
Considering the number of times he’s been portrayed, the caliber of the actors that have portrayed him, and his skin-crawling experiments, I’ll nominate Dr. Moreau.
Charles Laughton.
Burt Lancaster
Marlon Brando
And of course Dr. Mephesto
I have two favourites - Professor Farnsworth and Rotwang
Dr. Emilio Lizardo from The Adventures of Buckaroo Banzai Across the 8th Dimension.
Dr. Insano, with Rick Sanchez a close second.
Dr. Weird from Aqua Teen Hunger Force: “It begins!”
Magnus Pyke - very good science communicator and stereotypical mad boffin. http://www.itnsource.com/shotlist/ITVClips/1975/07/09/X09077501/?s=magnus+&st=0&pn=1
This guy (sorry for the poor quality):
First appearance at 1:50.Rick Sa<beeeelllllllCCCCH>nchez, bitches!
Newton was fairly mad. He died a virgin, believed in some sort of biblical ancient alien nonsense and likely burnt the only portrait of his famous scientific rival, Sir Robert Hooke.
OK, im exaggerating with the ancient aliens, but he did have some weird beliefs about the ancients and the bible.
For me, it’s Peter Cushing as Dr Frankenstein. Chilling!
Batman. Well, Batman’s a scientist (thank you, Homer) and he is pretty mad most of the time.
On serious reflection though I have to go with Lovecraft’s Herbert West.
Dr. Clayton Forrester of the Gizmonic Institute.
Let’s not forget Willy Wonka and Captain Nemo.
Even though you didn’t ask I’ll give you the worst mad scientist: Zarkov from the last Flash Gordon series. He was nothing more then creepy weirdo. A terrible bit of writing and acting.
He might be about the best. The great thing about him is he is never wanting for a test subject since he can experiment on himself.
It darn well better count. His science is sufficiently advanced to appear to be magic. Wicked dark magic. With no sense of shame.
It’s a tie between Rick Sanchez and Victor von Doom
Dr Flexi Jerkoff in the best porn flick ever:
