Well...
Can't go wrong with soundtracks. Personally, the soundtracks for Conan the Barbarian, 13th Warrior, and Lord of the Rings (all 3 for the current movies, plus the 1 for Bakshi's animated version) work great. I'd think that the soundtracks for movies such as Braveheart, Robin Hood: Prince of Thieves, the Last Samurai, Xena, & any other sort of near-genre entertainment (i.e., more historical/fantastical in nature) would work.
Soundtracks for movies/shows of exact/similar genres usually work well. For example, for sci-fi games (including WH40K), Star Wars, Star Trek, & other futuristic, sci-fi soundtracks would work well. For superhero games, soundtracks (or rather, scores) for movies like Batman, Spider-Man, Superman, etc., would work well.
As for more contemporary music, I'd say it more or less depend on the preferences of the group, & to a degree, the mood & theme of the moment in-game. Personally, I'm into heavy metal/rock & roll. Some really loud metal, IMHO, works great for battles--esp. against tough opponents (for example, I always thought that Static-X's "Bled For Days" would be a great background song for any sort of Wolverine/Sabretooth-like feral brawl in a superhero game; Rob Zombie's "Scum of the Earth" seems like a cool "theme song" for a bunch of low-life supervillains or recurring gang-like thugs; etc.).
However, I'd think that for a comedic game (whether it's a game of Paranoia, or just a humorous game/mini-campaign/big campaign), Weird Al music or similar stuff (like South Park soundtracks, Monty Python albums, Dr. Demento, etc.) would work great for adding atmosphere.
But, ultimately, using contempory music is up to you & your fellow players. There may be particular songs that could work, but rarely a full album--it'd more or less be a nice background noise/sound present, & not necessarily adding to the mood of the game.