Motorhead. Metal, and their most famous song is Ace of Spades, which should be easy to find on YouTube or something - Iron Fist is also a pretty amazing song.
Metallica. Metal. S&M, although being a live album, with songs that were post-1990, is pretty brilliant how they mix both an orchestra with metal. Apart from that, pretty cool.
New Model Army. Rock. Very wordy on politics and religion and all that, but I think they're really good and have a lot to show in their songs.
The Toy Dolls. Punk. It's less political than a lot of punk, but it's more comedic, and I personally love their songs, parodies and covers.
Enter Shikari. Alternative(?). Personally, I really love their fusion of dance music, proper instruments and screaming vocals, though on some songs they can go over the top.
Pendulum. Drum and Bass. Some songs have their instruments in them, my personal favourite being Propane Nightmares.
Pop Will Eat Itself. I'm notsure how to describe, I just really like their music.
Some of these seem popular and all that, but I live under a rock... so... fuck you! :D