I think you should head for a good book shop and look at what's offered. There are 2 good magazines in the UK I get, and 2 others that I bought but threw away. I also get the US Bike mag and even though it's obviously US-centric, I like the test reviews and reports, as generally, what's reported in the US will invariably get to the UK sometime after. There are different 'flavours' of mtb mag so look around and you're bound to find some you like.