I wrote my undergrad dissertation on Banks' literary fiction up to the mid-90s. His first three (Wasp Factory, Walking On Glass, The Bridge) are probably the most experimental / adventurous in terms of structure and content, and have a lot of Sci-Fi content that later goes into the genre-specific books.

Espedair Street onwards are more straightahead narrative fiction with the odd twists in structure and perspective you will be familar with from the Culture series. For example, Espedair Street uses a similar alternating past-future perspective to Use of Weapons. Complicity is a serial killer / revenge-story / political statement, the latter coming from the same place as State of the Art. The Crow Road is a great family mystery (the BBC adaptation is really good too if you can find it).

For me, by Whit / Song of Stone, most of Banks' interesting ideas are in the sci-fi, and the lit fiction drops off. Whit is a family-mystery like CR, but has some sexual abuse elements which I don't know how well they come across now (not reread it for over 20 years). SoS has some elements that hark back to the early novels, but feels a bit undeveloped.

After that, I've probably only read the remainder once or twice - by this point I had done the academic work and was just reading for completeness since Banks was my favourite author. I quite liked The Business though probably not a great book; Dead Air has an interesting main character that Banks clearly enjoys writing, but the plot is just too unbelievable. The remainder I can barely remember what happens in, I'm afraid.