Solve Media captcha
As everyone probably knows, the google reCaptcha is difficult to read (damn impossible a lot of the time), and I have been getting the odd bot/spammer getting through the default whmcs captcha, so we need different options for captcha.
I would like to put forward the option of adding an extra captcha systems:
Solve Media http://www.solvemedia.com/
It is far easier to read/work with than the reCaptcha system and I use it on all my other sites and have not had one issue with spam whilst using them.