I'd suggest the Cadillac Northstar would be on that list - they pretty regularly need a rear end seal at around 100k, which is something that requires removing

I'd suggest the Cadillac Northstar would be on that list - they pretty regularly need a rear end seal at around 100k, which is something that requires removing the entire engine. Conversely, there are many engines on there noted for their reliability, Ford Modular V8, for example, GM LS1, Ford Model T engine, VW Air-cooled Engine.