SurveyMonkey would be hugely helpful! I want the ability to use Marketo emails when sending my surveys but still get the information about knowing who filled it out, who started but didn't finish, and all the other fun things that I get when I use a SurveyMonkey email.
CVENT too for all my events! I'd much rather these 2 talk for all of our live events just like we use GTW for our webinars.