Preferred options for pushing data into Power BI

I am new to PowerBI.  Outside of having an excel document on my computer, what are the best options for pushing live data streams into PowerBI?   I tried the ODBC connector (to connecto to a MongoDB yesterday and that was amazingly slow.  Is the best option to simply have excel,csv files or are there better connectors that I should try to use than ODBC such as running everything possible through MySQL etc?