I'm pretty sure that when Descartes originally wrote this, he put it as "Dubito, ergo cogito, ergo sum". This makes a lot more sense for me, as Dubito means 'I doubt'.
I doubt, therefore I think, therefore I am.
The doubting part is the selling point for me. The premise of doubting means there is an ability to question life that proves thought and creativity (doubt), which is an inference that proves consciousness (think), which is an inference that proves being (am).
If a person can think creatively with doubt, then that proves being, at least to the self. I like to think about the robot comparison. A robot has a brain like a computer. This computer can make decisions and produce actions, but it cannot question (doubt) its own being. A robot is then not alive. But if a robot could question its own being and think creatively, which would then most likely inspire desire which would inspire emotion in that being, I would definitely say whoever created that robot is god because they just created life.
To sum up my stance, the addition of "Dubito/I doubt" makes it much more convincing for me to say Descartes brought up a valid and sound argument. I also love the quote in a superficial sense because it reminds me to think with doubt and use my creative thought, rather than go through the motions of life like so many people do #ROBOTS.