Hmm, the Pound... I could look up the currency conversion rate to US$, but still I have no idea where you look to find deals over there (across the pond?).
Good news is Pop is pretty easy, usually nice (maybe lush) mids will suit you well, and the same goes for EDM except that sometimes a little treble sparkle goes a long way. I've read a bunch of people have a lot of fun with the AKG K240, which I believe is semi-closed so leaks a bit less, read some reviews on that. The Creative Aurvana Live! headphones should be in budget and sound good too, Audio Technica AD900x should have some of the sparkle you're looking for if your head's not narrow and/or you're willing to bend the headband a bit for a good fit, Sennheiser HD558 is pretty balanced but somehow still musical, and... generally you're gonna have to see what you can afford, read the reviews on those models, and pick one that has a sound signature you think suits your taste.
All we can do is provide some of the reviews, and recommend ones that keyed into our tastes. I suggested above that you look into a few that seem interesting to me, but as of now I'd be looking for the one most resembling my current favorite. I can honestly say I enjoyed all the headphones I've owned for different reasons (not so much the HD201's I bought for my mom, and the KSC75s are good but I tend to forget I have them), but right now, for me, my taste, my broad music variety, if I had all my gear past and present in front of me and I wanted to listen to some/any music, I would reach for my Q701 (and tube amp).