If you like Knife Party, you might like the band's main project (Knife Party is a mini-project by two band members from a group named Pendulum.) They do fantastic drum and bass. Immersion, their most recent album, may be their best.
I absolutely love upbeat electronic music and it's awesome to know I'm not the only one on Hacker News! For over six months I've been scouring the music blogs and accumulating a playlist on Spotify. I think you'll love everything I have in here - feel free to subscribe!
Many already mentioned by others, but also Madeon and Hood Internet perhaps? 2 Many DJs mixes. Oh, and look up Paris DJs and if you like a bit of variety check out the Molested Laura mixes, especially #6. DJ Z Trip too.