different than having a or several hit records...

you can be a rapper/rap group, for instance, like NWA or PE back in the day who didn't have hit records because the majority of their material couldn't be played on mainstream radio but they still moved a lot of units...this applies to Prince early on. He did have a few hit records but most of his early material couldn't be played on the radio.

but

both NWA and PE sold boatloads of records nonetheless w/o having hit records

as long as you're commercially viable then yes you can still be considered a great artist but you have to have one or the other to be great...either you sell enough units or you've had hit records.

but

I don't know of any artist who ppl think is great that didn't sell many records or had hit records.