Glad to see some Pendulum in there, can't really say I enjoy their new album but the older stuff is classic.
Don't know much Happy Hardcore (although I enjoy the Alton Towers remix) but as for DnB there's a few great acts to check out.
DJ Fresh is great, and has done some collaberation with Pendulum, Gridlok is good, Noisia are great, Chase and Status are also pretty good.
http://www.mininova.org/tor/1069216
I strongly advise you download that torrent, it's an essential mix from Pendulum, loads of great artists on there including the ones I've mentioned, should give you a taste of a lot of stuff, essential mixes are great
And a song for you...
Sweet Dreams - Noisia Remix
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Edit - the_north_face advice is sound, but infected mushroom are psy/goatrance rather than DnB, still fantastic though, another good one by them is Avratz.