I just picked up some Audio Technica ATH-M50's that I really love; billions of times more accurate and detailed than my atrocious old Sony MDR-7506's (though that's not saying much ), and great sound isolation. Apparently semi-open headphones are more accurate and thus better for mixing, but I had to go fully-closed for situations like sweeping a mic in front of a cab or vocalists listening to their backing track while singing. AKG is really highly regarded in the headphone world, but I went with the AT's cuz they seemed like a better bang for my buck.
I love my Beyerdynamic DT770s! Not sure how much they go for on your side of the pond but based on the currency conversion it should be within your price range.
Yeah, I definitely would've gotten the Beyers if not for the price - $150 for the ATH-M50's vs. $240 for the DT770's, I gotta be choosy with my budget!
The Sennheiser HD25-II's are nice for mixing (especially the low end!), but they do get a bit uncomfortable in longer sessions. The back of the earcups is pressed on very hard by the headphones.