That is a tough question because much of what we consider to be good in SF is an acquired taste, or requires specific reading protocols, or both. Here are three novels that I highly recommend, that are absolutely SF but not typical, and might be accessible to the right reader:

The City & The City, by China Miéville
Among Others, by Jo Walton
Arctic Rising, by Tobias S. Buckell

One more that is classic space opera SF, but it is so excellent in every way, I would recommend it anyway:

Finders, by Melissa Scott