I just got a EMU 0404 sound card and a pair of Tapco S5 powered monitors. Both are excellent pieces of kit.
For only £64, there's no competition for a better two channel sound card. Maybe if all you want is gaming, get for something cheaper but for good sound and extensive music studio features, the 0404 is great. My only slight regret is that the connections are unbalanced.
I spent a lot of time looking for some active speakers but the S5's eventually won out over going with the cheaper Fostex PM0.4. It's a respected brand (Mackie) and has some good reviews (Sound on Sound). It's dual voltage which is important to me. It accepts RCA, TRS and XLR inputs and it has treble and bass filters. Each speaker is bi-amped with 60 watts for each driver so it can go very loud without distorting.
There's also a matching subwoofer I'd love to eventually pick up too (Tapco SW10).
The only problem I've found with them is that you can't place them too close to a computer monitor or the screen goes wavy. They are shielded but obviously it's not enough. They're also quite large for the desktop but smaller speakers won't offer enough bass. These go down to 60Hz.
So now I can blast tunes from either the computer or the SqueezeBox.