I completely agree - the IKEA dill mustard is quite delicious: the flavour is remarkably well balanced, and the mustard itself is creamy but still has a bit of bite to it.

My overall favourite mustard is Löwensenf extra sharf (extra hot) mustard. It's the one in the red bottle, and it's a good hot mustard - I find it's really hard to get a good hot mustard in North America, so that's my go to.

I did not find it outside of Hungary, yet, but there they have a mustard mixed with horseradish[1].

Since this type of mustard is unknown where I live, I tried to recreate it, but never achieved the same balance as in the commercial product, which is sad, because, in my opinion, it's a match made in heaven! It may be, that they use a milder mustard, than average, to balance out the hotness of the horseradish.

[1]: https://www.univer.hu/en/products/mustard/horseradish-mustar...

i know several varieties of beaver brand mustard have horseradish. example:

https://www.beavertonfoods.com/product/beaver-deli-mustard-1...

Maille has a horseradish mustard ("moutarde au raifort" in French), and it's one of my favorites.

Mustard mixed with horseradish is also common in Romania.

This is my Favorite, it’s a balsamic mustard http://foxsmarvelous.com/

It’s good enough to eat by itself on crackers alone.