Yea I’ve only read the first one myself. You did bring up a valid issue with the search function, I was just joking around :P
Although dark tower is a bit dark, no?
I really enjoyed reading TLWtaSAP.
Here’s my input:
Use of Weapons is great, and comes next in the publishing order.
Consider Phlebias is the first published culture novel and it is a good book. I read it first, but since it gives a more outsider perspective on the culture it probably wasn’t best to start with.
Either of those books is my recommendation, although be aware I’ve only read 4 of the 10 novels. Also as far as I know the books are generally self-contained and can really be read in any order, but there are some references you won’t get if you do so.