It very much depends on the Cooler, not all manufacturers are created equally! If it was a Corsair AIO then I wouldn’t bother, but with other manufacturers your mileage may vary.
You have good paste with the majority rather than the minority, unless you are buying some unknown brand. Corsair are not anything special compared to other main players.
Anything from the likes of Noctua, BeQuiet, Arctic, Alpenfohn, Alphacool, NZXT etc will be perfectly fine with the stock paste. Actually Noctua include the NT-H1 linked above with their coolers.
If you were overclocking and wanted the lowest temps then something like the Thermal Grizzly above would be a good shout. Looking at the initial post it doesn't seem like the op is going to be overclocking, so unless he has managed to ruin the pre-applied paste then he will be fine. No real need to spend an extra £8 for something he doesn't need.