If you for some reason were in Arkham, how would you escape it. 
As the Doctor!!!!!, I would befriend clayface, and wait intill a break out, and partner with clayface so nothing happens to me....

Find Batman :p

" Find Batman :p "

Never going too Arkham is the best why to escape.

With a toothpick, a string of floss, and five minutes time.

i would steal the heart of a doctor and have her sign that im ok 

Actually I would call for Candle Jack, he would help m-

Wow thats creative!!!! 
You can't just use Batman as your Get-Out-Jail-free card.

 I HOPE I HAVE THE POWER FROM Kitty Pryde!

Prove that I'm sane?

I would seduce someone. Duh. Hahaha...

Use science and study the whole prison.

"Use science and study the whole prison. "

" @Puzzle Master said:

"Use science and study the whole prison. "

Thats what a good genius would do.. "

Through a series of tubes.

telepathicly command the guards to let me out, then take a long  nap giving me time to get far far away.

I'd probably seduce one of the fine lady doctors and convince them to let me out and be my life mate... What? Joker did it.... 

Say I was sane and walk out the front door. No one would stop me.

steal Banes sh*t and bust out. I'll make stops to brake out others to distract Batman

Make every in the asylum to tremble in fear of the mighty Apocalypse! then command them to let me out :p 
ofcourse being realistic though i would go all Solid snake and sneak my way out and assasinate if nesecary.

Call Rick Deckard. If not available I'll go Macgyver or Chuck Greene on everyone and create something to bust my way out. 

Walk right out, seriously

Get someone to shine a flashlight from one roof to another and walk over it of course

I'd just walk out the front gate during one of the seemingly frequent break outs...That place really needs to up it's security and not rely on batman as much as the obviously do.

To everyone claiming they'd just prove their sanity, read the story in the secret files and origins villains from the late 90's...an innocent guy get's sent there and people keep telling him he's crazy. He eventually get's forced to sneak a fork to Joker, then sent to shock therapy, then he go's batshit crazy and kills ten inmates...right before Batman proved his innocence...but they had to keep him for obvious reasons...
If I had to break out of Arkham I would fake sanity, they are a very optimistic group, if you play along the doctors will totally declare you sane. How many times has Joker been let out? Or Two-Face...

id ask nicely xD