Coming from Finland, we've got 5 "major" beers: Koff, Karjala, Karhu, Lapin Kulta and Olvi; Karhu and Koff at least categorizing in the premium section, from those. There are a couple dozen different beers made here, and some of the smaller ones focusing on "quality", or another pinpoint.
I haven't really been looking for the "worst" beer, as I'll rather enjoy something else, given the choice, but from the Finnish ones I'd give the worst title to Lapin Kulta. It's not bad per se, but just an instinctual own taste; which I don't like that much. I don't like
Karjala, nor Olvi neither (I really really prefer cans over bottles), so the best are Koff, and Karhu, by far.
But Carlsberg Is still my main brand, and a bit of a favorite. Heineken being very close to that. Heineken costs a lot more here, but so far I've been very pleased with both III and IV from Heineken. Sandels is very good too.
Edit: almost forgot; Slots Guld is one of the least favorites as well. I know it's 5,9 and very cheap but still, it's not that good.