Right after World War II. Doing this from memory.
To Cincinnati - day train and night train. Used various names, Ohio Special/Michigan Special, Ponce de Leon, Queen City. Until about 1955 also a seaonsal train through to Florida, Florida Sunbeam, later New Royal Palm. The Cincinnati service lasted until 1958 or 1959.
To Indianapolis a night express, lasted until about '57 or '58.
To Cleveland - Mercury. Lasted until about 1959. Also, there were a number of trains between Detroit and Toledo to other points that had through cars to Cleveland and Pittsburgh.
Mercury morning run in each direction (lasted until about 1958). Twilight Ltd. same but late afternoon;made it into Amtrak era. Motor City Special, overnight train both directions.
Detroiter-all Pullman - gone about 1958. Empire State Express, lasted until about A-Day.
Chicago-Detroit-Buffalo and beyond.
Wolverine, NY Special (eastbound only), Fast Mail (westbound only)-morphed into the Michigan #335, Detroit-Chicago. NE Wolverine from Boston to Detroit westbound only. #364 Detroit-Buffalo. #358 Canadian/Niagara. #39 North Shore Ltd. NY-Chicago westbound, lasted a long time. Counterpart #40 probably only made it to about 1950.
Some nameless secondary locals and mail trains. Some of above trains in the Detroit-Chicago territory carried through cars from Toronto via CPR.
To Grand Rapids. Through cars on one postwar train Detroit to Jackson, then on local train to Grand Rapids. Thru sleeper from New York. This was an early RDC replacement; Jackson-GR turn.
To Mackinaw City. Day local to Bay City with through sleeper from New York. Another early RDC replacement and extended for a few years to Midland. Overnight Northerner to Mackinaw City. By early 1960s was a day time RDC run. Timberliner Friday only out, Sunday return put on after WWII and ran about 15 years. Until 1950 or so, Detroit and Mackinac through cars handled as far as Bay City.