What kind of work visa should a Canadian get for a marketing job in the US?

If you have a U.S. Bachelor’s degree or its equivalent, then you can look into the H1B visa. If you are already with a company, then you can look into the L1 visa for an intra-company transfer. If you have a substantial amount of money to invest, then the E visa could also be another option. The TN visa would not work for a marketing position.