I have the most experience marketing products.
I have the most experience in marketing.
Please check them.
Can we use "the most experience" during the interview or business meeting?
kumenglishI have the most experience
This means
I have more experience than anyone else.
I don't think you want to say that unless you really think you are the most experienced person in the world. 
Just say I have a lot of experience or I have a great deal of experience (in marketing).
However, you might be trying to say something else:
Most of my experience has been in marketing.
That's a different idea.
CJ
Comments
It is not correct.
I would say this.
I have worked in different roles, but the most of my experience has been in marketing.
The underlined portion is be a logical precedent.
Thank you, CJ.