I know Afri Kola (not much, only have had it a couple of times in Germany) and Fritz Kola (moree common in other countries, delicious, also other flavours, orange and apple are very very good).
Honestly, store brand are good enough.
Gaza cola is located in the UK and their profits go to hospitals in Gaza.
Freeway zero sugar from Lidl is pretty good and can probably be bought in a lot of European countries.
Cockta is very popular in former Yugoslavia countries.
We had a thing called Polo Cockta in Poland back in the day, supposedly based of Slovenian Cockta. It’s being sold again now but I assume that the brand owner coasts on nostalgia and I have no idea if it tastes anything like the old one. Do you know if yours is similar to the original formula?