Not Coke - PepsiMax.
Blended Scotches are okay with cola, but most Highland, Lowland and Speyside single malts are better.
Glenfiddich is terrible with or without cola.
And the Islay single malts aren't that crash hot with cola unless they are of the toned down type (e.g. Talisker Skye and Oban 14).
Regards,
Renato
Each to their own, but I really think you are missing out on one of life's great pleasures. Mixing fine whisky with soft drink is like buying a Ferrari and never taking it out of first gear, like going to a 3 hat restaurant and asking for steak and chips. Unlike wine (for me), with whisky once you spend a little money the difference can be just mind blowing. I've drank $200+ bottles of whisky that have been so smooth and so full of flavour that it has left me gobsmacked-I shudder at the thought of having that all masked with some sickly sweet syrup water..