Used to hack social accounts, Websites, Server Rooting ETC
don't use words like crack, it is more like the password is saved in some kind of md5 or something and then you have to crack it :P
writing from my personal experience.
1) You can try RATING, REMOTE ADMINISTRATION TOOL, victim needs to run that exe file, you can bind it with any software you like to share with victim, however if he has antivirus, your exe will be deleted, you need to use crypter in order to prevent the antivirus detection, once it runs in his computer, it will spread into system files also it will bind itself with explorer etc imp files, you will get all access, webcam, whole computer control, EVERYTHING. then gmail is not a big deal, i've done that :)
2) Try Keylogger, it will keep a log of every keystrokes, along with ENTER, TAB shortcut keys, you will know easily whatever he typed in password field.
3) There is another thing known as desktop phishing, search about it, i didn't try it yet, i left hacking ;)
4) There are some software which can be installed in your usb drive, you give that drive to victim, and then if he double click on the usb drive, it will save all the password in log.txt file he has saved in any browser, usually people tend to double click on any drive if they want to open it, however i don't coz i know if the root directory has the file of autorun then double click may lead to execution of desired exe file.
5) NOOB METHOD but worked for more than 90% for me, most of the people put real answer like where they are from? etc in security questions, i don't know if it still works or not, when i didn't know hacking i used to do this and it worked really well for me, i'm not sure now, you can easily guess some answers, by using forgotten id password.
6) IF VICTIM HAS ENABLED 2 STEP VERIFICATION THEN, FORGET IT DUDE, HAVE SOME MERCY ON HACKERS ;') however their is still a way.
nothing can be patched, everything can be hacked, everything can be patched, nothing can be hacked//
Hacking?? Oh my foot everyone can't hack . To do hacking you guys have to take knowledge about softwares and computer etc..etc… Im a born hacker I can hack anything but it doesnt mean you have to hack everyone's account. If you want to learn how to hack anything just text me on Feb I will give u a clue but u have that on your own…. My fb I'd is Bibaswayan Karmakar
Beat a guy until he tell the password.
Hacking is simple buddy… it know as physical hacking method.
I hope you guys njoying the answer.
Consultant (Google Cloud & Microsoft Office 365)
This is non answer type question and also if some one knows how to hack gmail he will better go for google bounty program instead of posting on quora.