Some sampling might be lazy, but there's plenty of impressive producers which take the art to the next level. Some suggestions you can sample: DJ Shadow, J Dilla, Madlib, The Avalanches, Statik Selektah. And as a bonus, an artist definitely not hip hop which makes beautiful use of sampling is Jens Lekman.

I will be charitable even though you called rap "lowest common denominator" poetry.

If you are genuinely interested, I suggest you look into the history of hip hop. IMO, the point of early hip hop was not to create sophisticated music, but to connect people by using sounds they were already familiar with. More important was the message and vocal delivery of the MC.