Firstly, have you recovered your e-mail account? If not (and I know it can be a lengthy process), get on it asap.
Once you've secured your e-mail account with a new password, then check it for alternative / back-up e-mail addresses. I know with hotmail you can have a back-up address to also recover the account from. Make sure this is an address you use (if you have an alternate e-mail).
Once your e-mail is recovered, try and recover your MC account through Minecraft.net (just goto login, then use the "can't remember password" link.)
If that doesn't work, then the hacker has probably changed the e-mail address associated with your account (apparently this is not possible with older accounts, but I have no idea how old they have to be). You will need to then contact them using this form -
http://help.mojang.com/customer/portal/emails/new - but you will need your transaction ID (i.e. a code given when you paid for your Minecraft account).
The support article is available here -
http://help.mojang.com/customer/portal/articles/361483-my-account-was-hackedPlease try and recover your accounts asap, otherwise it will reduce your chance of success, plus gives the hacker more time to use and abuse your account on any server they choose.